Intravenous fluids for reducing the duration of labour in low risk nulliparous women

  • Review
  • Intervention

Authors


Abstract

Background

Several factors may influence the progression of normal labour. It has been postulated that the routine administration of intravenous fluids to keep women adequately hydrated during labour may reduce the period of contraction and relaxation of the uterine muscle, and may ultimately reduce the duration of the labour. It has also been suggested that intravenous fluids may reduce caesarean sections (CS) for prolonged labour. 

However, the routine administration of intravenous fluids to labouring women has not been adequately elucidated although it is a widely-adopted policy, and there is no consensus on the type or volume of fluids that are required, or indeed, whether intravenous fluids are at all necessary. Women may be able to adequately hydrate themselves if they were allowed oral fluids during labour.

Furthermore, excessive volumes of intravenous fluids may pose risks to both the mother and her newborn and different fluids are associated with different risks.

Objectives

To evaluate whether the routine administration of intravenous fluids to low-risk nulliparous labouring women reduces the duration of labour and to evaluate the safety of intravenous fluids on maternal and neonatal health.

Search methods

We searched the Cochrane Pregnancy and Childbirth Group's Trials Register (13 February 2013).

Selection criteria

Randomised controlled trials of intravenous fluid administration to spontaneously labouring low-risk nulliparous women.

Data collection and analysis

The review authors independently assessed trials for inclusion, trial quality and extracted data.

Main results

We included nine randomised trials with 1781 women. Three trials had more than two treatment arms and were included in more than one comparison.

Two trials compared women randomised to receive up to 250 mL/hour of Ringer's lactate solution as well as oral intake versus oral intake only. For women delivering vaginally, there was a reduction in the duration of labour in the Ringer's lactate group (mean difference (MD) -28.86 minutes, 95% confidence interval (CI) -47.41 to -10.30). There was no statistical reduction in the number of CS in the Ringer's lactate group (risk ratio (RR), 0.73 95% CI 0.49 to 1.08).

Three trials compared women who received 125 mL/hour versus 250 mL/hour of intravenous fluids with free oral fluids in both groups. Women receiving a greater hourly volume of intravenous fluids (250 mL) had shorter labours than those receiving 125 mL (MD 23.87 minutes, 95% CI 3.72 to 44.02, 256 women). There was no statistically significant reduction in the number of CS in the 250 mL intravenous fluid group (average RR 1.00, 95% CI 0.54 to1.87, three studies, 334 women). In one study the number of assisted vaginal deliveries was lower in the group receiving 125 mL/hour (RR 0.47, 95% CI 0.27 to 0.81).

Four trials compared rates of intravenous fluids in women where oral intake was restricted (125 mL/hour versus 250 mL/hour). There was a reduction in the duration of labour in women who received the higher infusion rate (MD 105.61 minutes, 95% CI 53.19 to 158.02); P < 0.0001, however, findings must be interpreted with caution as there was high heterogeneity amongst trials (I2 = 53%). There was a significant reduction in CS in women receiving the higher rate of intravenous fluid infusion (RR 1.56, 95% CI 1.10 to 2.21; P = 0.01). There was no difference identified in the assisted delivery rate (RR 0.78, 95% CI 0.44 to 1.40). There was no clear difference between groups in the number of babies admitted to the NICU (RR 0.48, 95% CI 0.07 to 3.17).

Two trials compared normal saline versus 5% dextrose. Only one reported the mean duration of labour, and there was no strong evidence of a difference between groups (MD -12.00, 95% CI -30.09 to 6.09). A trial reporting the median suggested that the duration was reduced in the dextrose group. There was no significant difference in CS or assisted deliveries (RR 0.77, 95% CI 0.41 to 1.43, two studies, 284 women) and (RR 0.59, 95% CI 0.21 to 1.63, one study, 93 women) respectively. Only one trial reported on maternal hyponatraemia (serum sodium levels < 135 mmol/L ). For neonatal complications, there was no difference in the admission to NICU) or in low Apgar scores, however 33.3% of babies developed hyponatraemia in the dextrose group compared to 13.3 % in the normal saline group (RR 0.40, 95% CI 0.17 to 0.93) (P = 0.03). One trial reported a higher incidence of neonatal hyperbilirubinaemia in the dextrose group of babies. There was no difference in neonatal hypoglycaemic episodes between groups.

Authors' conclusions

Although the administration of intravenous fluids compared with oral intake alone demonstrated a reduction in the duration of labour, this finding emerged from only two trials. The findings of other trials suggest that if a policy of no oral intake is applied, then the duration of labour in nulliparous women may be shortened by the administration of intravenous fluids at a rate of 250 mL/hour rather than 125 mL/hour. However, it may be possible for women to simply increase their oral intake rather than being attached to a drip and we have to consider whether it is justifiable to persist with a policy of 'nil by mouth'. One trial raised concerns about the safety of dextrose and this needs further exploration.

None of the trials reported on the evaluation of maternal views of being attached to a drip during their entire labour. Furthermore, there was no objective assessment of dehydration. The evidence from this review does not provide robust evidence to recommend routine administration of intravenous fluids. Interpreting the results from trials was hampered by the low number of trials contributing data and by variation between trials. In trials where oral fluids were not restricted there was considerable variation in the amount of oral fluid consumed by women in different arms of the same trial, and between different trials. In addition, results from trials were not consistent and risk of bias varied. Some important research questions were addressed by single trials only, and important outcomes relating to maternal and infant morbidity were frequently not reported.

Résumé scientifique

Liquides par voie intraveineuse pour réduire la durée du travail chez les femmes nullipares à faible risque

Contexte

Plusieurs facteurs peuvent influer sur la progression du travail normal. On a émis l'hypothèse que l'administration systématique de liquides intraveineux pour maintenir les femmes correctement hydratées durant le travail pouvait réduire la période de contraction et de relâchement du muscle utérin et pouvait finalement réduire la durée du travail. Il a également été suggéré que les liquides intraveineux pouvaient réduire les césariennes pour le travail prolongé. 

Cependant, l'administration systématique de liquides intraveineux pour les femmes en travail n'a pas été expliquée de façon adéquate bien qu'il s'agisse d'une politique largement adoptée et il n'existe aucun consensus concernant le type ou le volume de liquides nécessaires ou en réalité concernant le fait de savoir si des liquides intraveineux sont vraiment nécessaires. Les femmes pourraient s'hydrater correctement elles-mêmes si elles étaient autorisées à consommer des liquides par voie orale durant le travail.

De plus, des volumes excessifs de liquides intraveineux peuvent représenter des risques à la fois pour la mère et son nouveau-né et des liquides différents sont associés à des risques différents.

Objectifs

Évaluer si l'administration systématique de liquides intraveineux à des femmes nullipares à faible risque en travail réduit la durée du travail et évaluer la sécurité des liquides intraveineux sur la santé de la mère et du nouveau-né.

Stratégie de recherche documentaire

Nous avons effectué des recherches dans le registre d'essais du groupe Cochrane sur la grossesse et la naissance (13 février 2013).

Critères de sélection

Les essais contrôlés randomisés portant sur l'administration de liquides intraveineux à des femmes nullipares à faible risque en travail spontané.

Recueil et analyse des données

Les auteurs de la revue ont indépendamment évalué les essais à inclure et leur qualité, et ont extrait les données.

Résultats principaux

Nous avons inclus neuf essais randomisés portant sur 1 781 femmes. Trois essais avaient plus de deux bras de traitement et étaient inclus dans plus d'une comparaison.

Deux essais comparaient des femmes randomisées pour recevoir jusqu'à 250 mL/heure d'une solution de lactate de Ringer, ainsi qu'une prise orale versus prise orale seule. Pour les femmes accouchant par voie basse, il y a eu une réduction de la durée du travail dans le groupe du lactate de Ringer (différence moyenne (DM) -28,86 minutes, intervalle de confiance (IC) à 95 % -47,41 à -10,30). Il n'y a eu aucune réduction statistique du nombre de césariennes dans le groupe du lactate de Ringer (risque relatif (RR) 0,73 ; IC à 95 % 0,49 à 1,08).

Trois essais comparaient des femmes qui recevaient 125 mL/heure versus 250 mL/heure de liquides intraveineux avec des liquides par voie orale en libre accès dans les deux groupes. Les femmes recevant un plus grand volume par heure de liquides intraveineux (250 mL) ont eu des durées de travail plus courtes que celles recevant 125 mL (DM 23,87 minutes, IC à 95 % 3,72 à 44,02, 256 femmes). Il n'y a eu aucune réduction statistiquement significative du nombre de césariennes dans le groupe des liquides intraveineux à 250 mL (RR moyen 1,00, IC à 95 % 0,54 à 1,87, trois études, 334 femmes). Dans une étude, le nombre d'accouchements assistés par voie basse était inférieur dans le groupe recevant 125 mL/heure (RR 0,47, IC à 95 % 0,27 à 0,81).

Quatre essais comparaient les débits de liquides intraveineux chez les femmes lorsque la prise orale était restreinte (125 mL/heure versus 250 mL/heure). Il y a eu une réduction de la durée du travail chez les femmes qui recevaient le débit de perfusion le plus élevé (DM 105,61 minutes, IC à 95 % 53,19 à 158,02) ; P < 0,0001, cependant, les résultats doivent être interprétés avec prudence, car on a observé une hétérogénéité importante entre les essais (I2 = 53 %). Il y a eu une réduction significative du nombre de césariennes chez les femmes recevant le débit de perfusion de liquides intraveineux le plus élevé ((RR 1,56 ; IC à 95 % 1,10 à 2,21 ; P = 0,01). Aucune différence n'a été identifiée en termes de taux d'accouchements assistés (RR 0,78, IC à 95 % 0,44 à 1,40). Il n'y a eu aucune différence nette entre les groupes concernant le nombre de bébés admis en UNSI (RR 0,48, IC à 95 % 0,07 à 3,17).

Deux essais comparaient une solution saline normale versus 5 % de dextrose. Un seul a rapporté la durée moyenne de travail et il n'y a pas eu de preuves solides d'une différence entre les groupes (DM -12,00, IC à 95 % -30,09 à 6,09). Un essai rapportant la médiane a suggéré que la durée était réduite dans le groupe sous dextrose. Il n'y a eu aucune différence significative en termes de césariennes ou d'accouchements assistés (RR 0,77, IC à 95 % 0,41 à 1,43, deux études, 284 femmes) et (RR 0,59, IC à 95 % 0,21 à 1,63, une étude, 93 femmes) respectivement. Un seul essai a rapporté l'hyponatrémie de la mère (taux de sodium dans le sérum < 135 mmol/L ). Pour les complications néonatales, il n'y a eu aucune différence en termes d'admission en UNSI ou de faibles scores Apgar, cependant 33,3 % des bébés ont développé une hyponatrémie dans le groupe sous dextrose contre 13,3 % dans le groupe sous solution saline normale (RR 0,40, IC à 95 % 0,17 à 0,93) (P = 0,03). Un essai a rapporté une plus grande incidence de l'hyperbilirubinémie néonatale dans le groupe de bébés sous dextrose. Il n'y a eu aucune différence en termes d'épisodes hypoglycémiques entre les groupes.

Conclusions des auteurs

Bien que l'administration de liquides intraveineux comparée à la prise orale seule ait démontré une réduction de la durée du travail, ce résultat n'a été obtenu qu'à partir de deux essais. Les résultats d'autres essais suggèrent que si une politique d'absence de prise orale est appliquée, alors la durée du travail chez les femmes nullipares peut être raccourcie par l'administration de liquides intraveineux à un débit de 250 mL/heure plutôt que 125 mL/heure. Cependant, il est possible pour les femmes d'augmenter simplement leur prise orale plutôt que d'être reliées à un goutte à goutte et nous devons déterminer s'il est justifiable de persister à appliquer une politique de « rien dans la bouche ». Un essai a soulevé des inquiétudes concernant la sécurité du dextrose et cela doit faire l'objet d'une exploration plus poussée.

Aucun des essais n'a rendu compte de l'évaluation de l'avis des mères concernant le fait d'être reliées à un goutte à goutte pendant tout leur travail. De plus, il n'y a eu aucune évaluation objective de la déshydratation. Cette revue ne fournit pas de preuves solides permettant de recommander une administration systématique de liquides intraveineux. L'interprétation des résultats des essais a été gênée par le faible nombre d'essais ayant fourni des données et par la variation entre les essais. Dans les essais où les liquides par voie orale n'ont pas été restreints, il y a eu une variation considérable de la quantité de liquide par voie orale consommée par les femmes dans différents bras du même essai et entre différents essais. De plus, les résultats des essais n'ont pas été cohérents et le risque de biais a été variable. D'importantes questions de recherche n'ont été abordées que par des essais uniques et, fréquemment, d'importants résultats concernant la morbidité chez la mère et le nourrisson n'ont pas été rapportés.

Plain language summary

Intravenous fluids for preventing prolonged labour in women giving birth to their first baby

Labour may be considered to be a period of prolonged exercise. Labouring women may become dehydrated as a result of the physical exertion caused by the muscles of the womb contracting. In many institutions women are subjected to a questionable policy of restricted oral intake. Only sips of water or ice chips are allowed. In institutions where this is employed, women are given routine intravenous fluids (through a "drip").The aim of this review was to evaluate the impact of the routine administration of intravenous fluids (using a 'drip') on the duration of labour in women who were in their first pregnancy. We also wanted to determine any side-effects of intravenous fluids on the mother and the newborn.

We included nine randomised controlled trials.The review demonstrated that in women who are not freely drinking fluids during the course of their labour, additional fluids through a 'drip' (intravenously) reduces the duration of their labour. The number of caesarean sections was also reduced when women received normal saline or Ringer’s lactate at a rate of 250 mL/hour compared to 125 mL/hour. Dextrose-containing fluids reduced the sodium levels (hyponatraemia) of both the labouring mother and their newborns.

However, the differences in the methodology and quality of several of the trials do not provide sufficient evidence to recommend routinely attaching labouring women to a drip. Further research needs to be undertaken as to whether or not women who are freely drinking, even need to have a drip, and the policy of restricted oral intake needs to be urgently reviewed.

Résumé simplifié

Liquides par voie intraveineuse pour prévenir le travail prolongé chez les femmes accouchant de leur premier bébé

Le travail peut être considéré comme une période d'exercice prolongé. Les femmes en travail peuvent se déshydrater en raison de l'effort physique provoqué par la contraction des muscles de l'utérus. Dans de nombreuses institutions, les femmes sont soumises à une politique douteuse de restriction de la prise orale. Seules des gorgées d'eau ou des copeaux de glace sont autorisés. Dans les institutions où cette politique est utilisée, les femmes reçoivent de façon systématique des liquides par voie intraveineuse (au moyen d'un « goutte à goutte »). L'objectif de cette revue était d'évaluer l'impact de l'administration systématique de liquides par voie intraveineuse (au moyen d'un « goutte à goutte ») sur la durée du travail chez les femmes pour lesquelles il s'agissait de la première grossesse. Nous avons également voulu déterminer les effets secondaires de l'administration de liquides par voie intraveineuse sur la mère et le nouveau-né.

Nous avons inclus neuf essais contrôlés randomisés. La revue a démontré que, chez les femmes qui ne buvaient pas de liquides librement au cours de leur travail, des liquides supplémentaires à travers un « goutte à goutte » (en intraveineuse) réduisaient la durée de leur travail. Le nombre de césariennes a également été réduit lorsque les femmes ont reçu une solution saline normale ou du lactate de Ringer à un débit de 250 mL/heure comparé à 125 mL/heure. Les liquides contenant du dextrose ont réduit les taux de sodium (hyponatrémie) à la fois chez les mères en travail et leurs nouveau-nés.

Cependant, les différences de méthodologie et de qualité de plusieurs essais ne fournissent pas suffisamment de preuves pour recommander de relier de façon systématique les femmes en travail à un goutte à goutte. Des recherches supplémentaires doivent être réalisées pour déterminer si les femmes qui boivent librement ont vraiment besoin d'un goutte à goutte et la politique de restriction de la prise orale doit être révisée de façon urgente.

Notes de traduction

Traduit par: French Cochrane Centre 7th August, 2013
Traduction financée par: Pour la France : Minist�re de la Sant�. Pour le Canada : Instituts de recherche en sant� du Canada, minist�re de la Sant� du Qu�bec, Fonds de recherche de Qu�bec-Sant� et Institut national d'excellence en sant� et en services sociaux.

Laički sažetak

Infuzija tekućine za skraćivanje prvog poroda

Porođaj se može promatrati kao produljena tjelovježba. Žene tijekom porođaja mogu dehidrirati zbog fizičkog napora koji nastaje zbog stezanja mišića maternice. U mnogim ustanovama ženama se ograničava pijenje tijekom porođaja, što je vrlo upitna praksa. Često su dozvoljeni samo mali gutljaji vode ili sitnih komadića leda. U ustanovama koje provode takvu praksu, ženama se tekućina rutinski daje putem infuzije. Cilj Cochrane sustavnog pregleda bio je procijeniti učinak rutinske primjene intravenske tekućine na trajanje porođaja u žena kojima je to prva trudnoća. Također je procijenjeno ima li intravenska infuzija tekućine ikakve nuspojave za majku i novorođenče.

Uključeno je 9 randomiziranih kontroliranih ispitivanja. Sustavnim pregledom pokazalo se da u žena koje ne piju slobodno tekućinu tijekom porođaja, dodatno davanje tekućine intravenskim putem skraćuje trajanje porođaja. Broj carskih rezova također je smanjen u žena koje su primale fiziološku otopinu ili Ringerovu otopinu u dozi od 250 ml na sat, u usporedbi s onima koje su primale upola manji volumen tekućine. Tekućine koje su sadržavale dekstrozu smanjile su razinu natrija i u žena i u njihove novorođenčadi.

Međutim, razlike u metodologiji i kvaliteti analiziranih istraživanja ne daju dovoljno dokaza da bi se davanje tekućine infuzijom moglo preporučiti kao rutinski postupak tijekom porođaja. Potrebna su dodatna istraživanja da bi se utvrdilo da li žene koje slobodno mogu piti koliko god žele tekućine uopće trebaju dodatnu tekućinu putem infuzije. Isto tako je hitno potrebno razmotriti praksu kojom se ženama ograničava pijenje tekućine tijekom porođaja.

Bilješke prijevoda

Prevoditelj:: Croatian Branch of the Italian Cochrane Centre

Background

Description of the condition

Human labour is physically demanding and there are several factors that may influence the normal progression of labour. One of the rationales for administering intravenous fluids during labour is the need to provide an adequate metabolic environment to support the demands of labour. While the physiological calorific requirement for a labouring uterus has been reported to be approximately ten grams of carbohydrates per hour (Morton 1985), the actual amount of hydration that a labouring uterus requires for efficient contraction, has not been quantified. It does seem logical that adequate hydration and perhaps supplemental glucose is required to maintain endurance and muscle efficiency during the process of labour and parturition, but is the routine administration of intravenous fluids entirely necessary?

The labouring uterine smooth muscle may be compared to periods of prolonged exertion as is seen with prolonged exercise, for example, in distance runners. Several prospective randomised trials in the field of sports medicine have demonstrated that regular fluid replacement during exercise improved performance and prevented dehydration in long-distance runners (Barr 1991; Maughan 1996; Montain 1992). Some researchers believe that extrapolating data from exercise physiology to uterine smooth muscle, may provide some insight as to why some women who may be inadequately hydrated undergo prolonged labours (Saltin 1998). During exercise, fluid loss is poorly regulated and moreover, the rate of fluid loss by sweating and respiration is not reduced in a state of dehydration (Garite 2000). More specifically, uterine blood flow is not autoregulated and in the presence of decreased intravascular volume (which may occur secondary to dehydration), fluid may be redistributed away from the uterus potentially aggravating the problem (Eslamian 2006). Optimal uterine perfusion is not only required for adequate fetal oxygenation, but also for the delivery of nutrients and the elimination of waste products from the contracting myometrium. Furthermore, labouring women who are not adequately hydrated may have alterations in the acid-base balance of the fluid surrounding the myometrial fibres resulting in a decrease in the pH. Changes in the pH have been shown to affect calcium signalling and the force of myometrial contractility, prolonging the course of labour (Pierce 2003).

Some studies have therefore postulated that dysfunctional or prolonged labour, a leading indication for primary caesarean section delivery, could, at least in part, be caused by inadequate uterine forces or inappropriately co-ordinated contractions because of inadequate hydration. The hypothesis that was developed was that women who are adequately hydrated with routine administration of intravenous fluids, have a reduced duration of labour and a reduced need for caesarean section delivery for prolonged labour (Eslamian 2006; Garite 2000). This theory raises several questions: can intravenous fluids be proven to reduce the duration of labour and caesarean section delivery for prolonged labour? If so, what is the optimal rate and optimal type of intravenous fluid to be administered to labouring women? Are there any associated risk factors with routine intravenous fluid administration?

Indeed the benefits of routine administration of intravenous fluids to low-risk labouring women have not been properly evaluated. Despite the lack of evidence, many institutions have adopted the policy of restricting women from food and drink in labour and replacing oral intake with intravenous fluids instead. Another purported reason for enforcing a policy of nil by mouth is that it is a protective measure against aspiration of gastric contents in the event of general anaesthesia. However, the advent of epidural anaesthesia and antacids has greatly reduced the risk of pulmonary complications and the attendant morbidity from the aspiration of pulmonary contents has virtually disappeared (O'Sullivan 2003). The likelihood of mortality from aspiration during caesarean section has been quoted as 1.8 per 100,000 (Schuitemaker 1997), and adjusted for the vastly reduced number of general anaesthetics, the actual risk is even lower at 1 in 1.2 million. (Romano 2009). Despite a revision of guidelines from the American Society of Anesthesiologists (ASA 2007) to encourage the oral intake of clear fluids in labour, almost 83% of women in America are routinely given intravenous fluids instead, even if they were deemed low risk (Romano 2009).

Practices vary amongst different countries. Many midwifery-led units in the UK at least, do not routinely administer intravenous fluids for low-risk women and neither is it a common practice in home births and some birth centres (Michael 1991). A survey that was conducted in around 350 units in England and Wales revealed that a third allowed some food or drink and well over 90% allowed some oral intake (Michael 1991). In the Netherlands too, women have been allowed unrestricted oral intake (Scheepers 1998). While it is acknowledged that labour is a demanding event, and in some cases may be prolonged, should women be routinely supplemented with intravenous fluids or could this be simply avoided by allowing women to eat and drink according to their own feelings of hunger or thirst? Whether or not restricting oral food intake is justifiable is the subject of another review (Singata 2010).

Besides medicalising a normal labour, women may find intravenous fluids uncomfortable and being attached to an intravenous line limits mobility. Furthermore, intravenous infusions can lead to elevated central venous pressure after the administration of only one to two litres of fluid. Fluid overload has also been associated with increased cardiovascular work and pulmonary oedema (Carvalho 1994).There are also concerns that excessive fluids administered to the mother, may affect the newborn as well. More recent studies found that if mothers received more than 200 mL/hour of fluids, their babies were 3.2 times more likely to experience excess weight loss at three days compared to mothers who had less than 100 mL/hour of fluids (Chantry 2011; Noel-Weiss 2011).

The aim of this review was to evaluate the impact of routine administration of intravenous fluids to low-risk nulliparous labouring women. We also aimed to explore the safety of the mother and the baby.

Description of the intervention

The intervention that we reviewed is the routine administration of fluids through an intravenous line (drip) to low-risk nulliparous women in labour. This review focuses specifically on the routine use of intravenous administration of fluids during labour for the purpose of fluid and nutritional support/management and not for clinical conditions where intravenous fluids are medically indicated, for example, as preload prior to epidural analgesia, or for any other medical interventions such as cardio-respiratory conditions, diabetes, haematological or renal disease.  Neither did we consider the use of intravenous fluids for women with a febrile illness or pyrexia during labour.  

There are different types of intravenous fluids that may be employed and there are side-effects that are associated with some. For example, although high-dose glucose solutions may correct maternal ketosis, the administration thereof may be associated with an increased incidence of neonatal hyponatraemia (Tarnow-Mordi 1981). Dextrose-only solutions may also cause maternal hyponatraemia and affect serum osmolality (Keppler 1988).

Different volumes of fluids may also be used. Excessive amounts of fluids may lead to fluid overload (Montain 2008) in the mother. There are also concerns over newborn weight loss during the first three days following birth that occurs when mothers have received large volumes of intravenous fluids (Chantry 2011; Noel-Weiss 2011).

While intravenous fluids may seem a simple and benign intervention to healthcare professionals, routine intravenous fluids may adversely affect the perception of labour for women and negatively impact on the normality of labour. We therefore also planned to evaluate the qualitative disadvantages of routine intravenous fluids which include women being less mobile in labour, maternal discomfort, fear and pain and overall negative feelings.

How the intervention might work

As already discussed above, some women may become very dehydrated during labour as the uterine muscle has to contract and relax continuously and this may be required for a prolonged period of time. The intense exertion that may be required may lead to dehydration. Adequate fluid replacement enhances muscle performance in long-distance runners. The administration of intravenous fluids to keep women adequately hydrated during labour may reduce the period of contraction and relaxation of the uterine muscle and may ultimately reduce the duration of the labour.

It has been postulated that dehydration may contribute to prolonged and inefficient labour and it can be hypothesised that adequate maternal hydration will be important for optimum oxygenation, delivery of nutrients and elimination of waste products from the contracting myometrium. It has also been suggested that adequate intravenous fluid replacement regimens may even obviate the need for caesarean sections that are performed solely for “failure to progress” in labour, or prolonged labour (Eslamian 2006) that may result from inadequate hydration. Some types of intravenous fluids (dextrose-containing solutions), may also provide a calorific supplementation for labouring women.

However, the notion that the administration of routine intravenous fluids may prevent operative deliveries by preventing dehydration is largely theoretical as operative deliveries may result from various factors. However, even if there is a partial benefit of intravenous fluids in the reduction of unnecessary caesarean sections then it is important to evaluate this as there are wider cost implications as well as the impact on future pregnancies.

Why it is important to do this review

As outlined above, in many centres, the use of routine intravenous fluids administration is widespread and pervasive without a cogent body of evidence. Furthermore, little cognisance has been noted regarding the safety and efficacy of routine intravenous fluids, and indeed the potential dangers of some types of fluids. Although oral fluids are the simplest and easiest way of replenishing lost fluids, it is thought that amounts of more than 500 mL/hour are required in prolonged exertion (Noakes 1993) such as labour. Thus, there may be some justification for the routine use of intravenous fluids for labouring women, however, the volumes and types of fluids need further clarification. The main aim of this review is to determine the impact (if any) on the use of routine intravenous fluid administration on the duration of labour. Different types of intravenous fluid regimens may produce different results for women in labour. The type and volume of intravenous fluid that is administered during labour need to be elucidated. Moreover, this review is important as it may assist in providing evidence that routine intravenous fluid administration is not superior to unrestricted oral intake in low-risk women.

Objectives

  • To assess the impact of early or routine intravenous fluid administration on the duration and course of labour.

  • To determine the risks and benefits of early or routine intravenous fluid administration during labour.

  • To determine the risks and benefits of different fluid regimens (i.e. different volumes or different types of fluids, or both) used in labour.

  • To compare the course of labour when intravenous fluids are compared with oral intake.

  • To compare the course of labour when oral intake is supplemented by routine intravenous fluids versus oral intake only.

Methods

Criteria for considering studies for this review

Types of studies

  • Randomised and quasi-randomised studies comparing the administration of routine intravenous fluids compared with non-administration of intravenous fluids

  • Randomised and quasi-randomised studies comparing the administration of different volumes of the same intravenous fluids

  • Randomised and quasi-randomised studies comparing the administration of different intravenous fluids

Since this review aims to determine whether the routine use of intravenous fluids shortens the duration of labour or minimises the need for augmentation of labour, women who subsequently require oxytocin augmentation have not been excluded. However, women who require oxytocin primarily for induction of labour were excluded. Therefore, we included caesarean sections, other operative deliveries and the need for augmentation as outcome measures.

We have not included cross-over trials; this research design is not suitable for this intervention during labour.

Types of participants

  • Nulliparous women

We intentionally restricted the review to nulliparous women as we felt that the inclusion of multiparous women would introduce a considerable bias as this would include women in their second, third or fourth labours. The main aim of the review is to determine whether intravenous fluids reduce the duration of labour. It is generally accepted that women tend to labour quicker in subsequent labours and this would have introduced a bias. It would have been difficult to determine the influence that a woman's parity had on the duration of labour. Therefore, to exclude this bias and for the sake of uniformity, we only included low-risk nulliparous women.

  • Spontaneous active labour

  • Singleton presentations

  • Cephalic presentation

  • Term pregnancies (greater than 36 weeks)

  • Low-risk pregnancies (i.e. no medical conditions such as diabetes, pre-eclampsia etc and no obstetric problems such as antepartum haemorrhage or chorioamnionitis)

Types of interventions

  • Intravenous fluid versus no intravenous fluids (restricted oral intake)

  • Intravenous fluids versus no intravenous fluids (oral intake not restricted)

  • Intravenous fluids + oral intake versus intravenous fluids alone

  • Intravenous fluids + oral intake versus oral intake alone

  • Comparison of different rates of intravenous fluids

  • Comparison of different types of intravenous fluids

Types of outcome measures

The outcomes were divided into maternal and fetal outcomes.

Primary outcomes
Maternal
  1. Duration of labour (in minutes)

  2. Fluid overload

  3. Caesarean section

  4. Assisted delivery

Fetal
  1. Admission to neonatal intensive care unit (NICU)/special care baby unit

  2. Low Apgar scores (less than seven at five minutes)

  3. Cord pH < 7.0

  4. Newborn weight loss (first three days)

Secondary outcomes
Maternal
  1. Maternal comfort

  2. Maternal satisfaction

  3. Subjective feelings of thirst

  4. Ketoacidosis

Fetal and neonatal
  1. Hyponatraemia

  2. Hyperbilirubinaemia

Search methods for identification of studies

Electronic searches

We contacted the Trials Search Co-ordinator to search the Cochrane Pregnancy and Childbirth Group’s Trials Register (13 February 2013). 

The Cochrane Pregnancy and Childbirth Group’s Trials Register is maintained by the Trials Search Co-ordinator and contains trials identified from:

  1. monthly searches of the Cochrane Central Register of Controlled Trials (CENTRAL);

  2. weekly searches of MEDLINE;

  3. weekly searches of EMBASE;

  4. handsearches of 30 journals and the proceedings of major conferences;

  5. weekly current awareness alerts for a further 44 journals plus monthly BioMed Central email alerts.

Details of the search strategies for CENTRAL, MEDLINE and EMBASE, the list of handsearched journals and conference proceedings, and the list of journals reviewed via the current awareness service can be found in the ‘Specialized Register’ section within the editorial information about the Cochrane Pregnancy and Childbirth Group.

Trials identified through the searching activities described above are each assigned to a review topic (or topics). The Trials Search Co-ordinator searches the register for each review using the topic list rather than keywords. 

We will not apply any language restrictions.

Data collection and analysis

Selection of studies

All review authors (Feroza Dawood (FD), Therese Dowsell (TD) and Siobhan Quenby (SQ)) independently assessed for inclusion all the potential studies identified as a result of the search strategy. Disagreement was resolved through discussion.

Data extraction and management

We designed a data extraction form to capture data. For eligible studies, FD ,TD and SQ extracted the data using the agreed form. We resolved discrepancies through discussion. We entered data into Review Manager software (RevMan 2011) and checked for accuracy.

Assessment of risk of bias in included studies

Two review authors independently assessed risk of bias for each study using the criteria outlined in the Cochrane Handbook for Systematic Reviews of Interventions (Higgins 2011). We resolved any disagreement by discussion.

(1) Random sequence generation (checking for possible selection bias)

We have described for each included study the method used to generate the allocation sequence in sufficient detail to allow an assessment of whether it should produce comparable groups.

We assessed the method as:

  • low risk of bias (any truly random process, e.g. random number table; computer random number generator);

  • high risk of bias (any non-random process, e.g. odd or even date of birth; hospital or clinic record number);

  • unclear risk of bias.   

(2) Allocation concealment (checking for possible selection bias)

We have described for each included study the method used to conceal allocation to interventions prior to assignment and assess whether intervention allocation could have been foreseen in advance of, or during recruitment, or changed after assignment.

We assessed the methods as:

  • low risk of bias (e.g. telephone or central randomisation; consecutively numbered sealed opaque envelopes);

  • high risk of bias (open random allocation; unsealed or non-opaque envelopes, alternation; date of birth);

  • unclear risk of bias.   

(3.1) Blinding of participants and personnel (checking for possible performance bias)

We have described for each included study the methods used, if any, to blind study participants and personnel from knowledge of which intervention a participant received. We considered studies to be at low risk of bias if they were blinded, or if we judged that the lack of blinding would be unlikely to affect results. We assessed blinding separately for different outcomes or classes of outcomes.

We assessed the methods as:

  • low, high or unclear risk of bias for participants;

  • low, high or unclear risk of bias for personnel;

(3.2) Blinding of outcome assessment (checking for possible detection bias)

We have described for each included study the methods used, if any, to blind outcome assessors from knowledge of which intervention a participant received.  We assessed blinding separately for different outcomes or classes of outcomes.

We assessed the methods used to blind outcome assessment as:

  • low, high or unclear risk of bias.

(4) Incomplete outcome data (checking for possible attrition bias due to the amount, nature and handling of incomplete outcome data)

We have described for each included study, and for each outcome or class of outcomes, the completeness of data including attrition and exclusions from the analysis. We have stated whether attrition and exclusions were reported and the numbers included in the analysis at each stage (compared with the total randomised participants), reasons for attrition or exclusion where reported, and whether missing data were balanced across groups or were related to outcomes. Where sufficient information was reported, or was supplied by the trial authors, we re-included missing data in the analyses which we undertook.

We assessed methods as:

  • low risk of bias (e.g. no missing outcome data; missing outcome data balanced across groups);

  • high risk of bias (e.g. numbers or reasons for missing data imbalanced across groups; ‘as treated’ analysis done with substantial departure of intervention received from that assigned at randomisation);

  • unclear risk of bias.

(5) Selective reporting (checking for reporting bias)

We have described for each included study how we investigated the possibility of selective outcome reporting bias and what we found.

We assessed the methods as:

  • low risk of bias (where it is clear that all of the study’s pre-specified outcomes and all expected outcomes of interest to the review have been reported);

  • high risk of bias (where not all the study’s pre-specified outcomes have been reported; one or more reported primary outcomes were not pre-specified; outcomes of interest are reported incompletely and so cannot be used; study fails to include results of a key outcome that would have been expected to have been reported);

  • unclear risk of bias.

(6) Other bias (checking for bias due to problems not covered by (1) to (5) above)

We have described for each included study any important concerns we had about other possible sources of bias.

We assessed whether each study was free of other problems that could put it at risk of bias:

  • low risk of other bias;

  • high risk of other bias;

  • unclear whether there is risk of other bias.

(7) Overall risk of bias

We made explicit judgements about whether studies are at high risk of bias, according to the criteria given in the Handbook (Higgins 2011). With reference to (1) to (6) above, we assessed the likely magnitude and direction of the bias and whether we considered it was likely to impact on the findings. We explored the impact of the level of bias through undertaking sensitivity analyses - see Sensitivity analysis

Measures of treatment effect

Dichotomous data

For dichotomous data, we have presented results as summary risk ratio with 95% confidence intervals. 

Continuous data

For continuous data, we used the mean difference if outcomes were measured in the same way between trials. We planned to use the standardised mean difference to combine trials that measured the same outcome, but used different methods.  

Unit of analysis issues

Cluster-randomised trials

We did not anticipate any cluster-randomised trials on this topic. However, if we identify any cluster-randomised trials in future updates of this review they will be included in the analyses along with individually-randomised trials. We will adjust their sample sizes using the methods described in the Handbook (Higgins 2011) using an estimate of the intracluster correlation co-efficient (ICC) derived from the trial (if possible), from a similar trial or from a study of a similar population. If we use ICCs from other sources, we will report this and conduct sensitivity analyses to investigate the effect of variation in the ICC. If we identify both cluster-randomised trials and individually-randomised trials, we plan to synthesise the relevant information. We will consider it reasonable to combine the results from both if there is little heterogeneity between the study designs and the interaction between the effect of intervention and the choice of randomisation unit is considered to be unlikely.

We will also acknowledge heterogeneity in the randomisation unit and perform a subgroup analysis to investigate the effects of the randomisation unit.

Cross-over trials 

We did not include cross-over trials.

Dealing with missing data

For included studies, we noted levels of attrition. We planned to explore the impact of including studies with high levels of missing data in the overall assessment of treatment effect by using sensitivity analysis; however, in this version of the review most of the trials had low levels of attrition and we did not carry out this planned analysis.

For all outcomes, we carried out analyses, as far as possible, on an intention-to-treat basis, i.e. we attempted to include all participants randomised to each group in the analyses. The denominator for each outcome in each trial was the number randomised minus any participants whose outcomes were known to be missing ('available case' analysis).

We analysed data on all participants with available data in the group to which they were allocated, regardless of whether or not they received the allocated intervention. If in the original reports participants were not analysed in the group to which they were randomised, and there was sufficient information in the trial report, we would have attempted to restore them to the correct group.

Assessment of heterogeneity

We examined statistical heterogeneity in each meta-analysis using the T², I² and Chi² statistics. We regarded heterogeneity as substantial if the T² was greater than zero and either an I² was greater than 30% or there was a low P value (less than 0.10) in the Chi² test for heterogeneity. In the presence of heterogeneity, we have used a random-effects meta-analysis as an overall summary if calculating an average treatment effect was considered appropriate.

Assessment of reporting biases

In future updates of this review, if there are 10 or more studies in the meta-analysis we will investigate reporting biases (such as publication bias) using funnel plots. We will assess funnel plot asymmetry visually, and use formal tests for funnel plot asymmetry. For continuous outcomes we will use the test proposed by Egger 1997, and for dichotomous outcomes we will use the test proposed by Harbord 2006. If asymmetry is detected in any of these tests or is suggested by a visual assessment, we will perform exploratory analyses to investigate it.

Data synthesis

We carried out statistical analysis using the Review Manager software (RevMan 2011). We used fixed-effect meta-analysis for combining data where trials examined the same intervention, and the trials' populations and methods were judged sufficiently similar. Where we suspected clinical or methodological heterogeneity between studies sufficient to suggest that treatment effects may differ among trials, we used random-effects meta-analysis.

If we identified substantial heterogeneity in a fixed-effect meta-analysis we noted this and repeated the analysis using a random-effects method, when appropriate. Where we used random-effects analyses, the results are presented as the average treatment effect with its 95% confidence interval, along with the estimates of I².

Subgroup analysis and investigation of heterogeneity

If we had identified substantial heterogeneity, we planned to investigate it using subgroup analyses and sensitivity analyses.

We planned to assess differences between subgroups by interaction tests. In this version of the review too few studies contributed data to allow this additional analysis.

Sensitivity analysis

We planned to carry out sensitivity analyses to explore the effect of trial quality for important outcomes in the review. Where there was risk of bias associated with a particular aspect of study quality (e.g. quasi-randomisation or high risk of bias for allocation concealment), we planned to explore this by sensitivity analyses using the primary outcomes. However, in this version of the review only a very limited number of studies contributed data for each outcome and so we did not carry out this planned analysis. In future updates, as more data become available, we will carry out these additional analyses.

Results

Description of studies

We included nine trials that collectively recruited 1781 women. However, due to attrition and various exclusion factors, the final analysis in this review is based on 1617 women.

Results of the search

We included nine trials and excluded 26 trials.

Included studies

Nine trials (Alavi 2005; Coco 2010; Direkvand-Moghadam 2012; Eslamian 2006; Garite 2000; Kavitha 2012; Maderia 2007; Shrivastava 2009; Stratton 1995) were included in this review. Collectively, a total of 1781 women were initially recruited, however due to attrition and exclusion, the final analysis is based on 1617 women. For full details, see Characteristics of included studies.

Participants

All women were spontaneously labouring low-risk nulliparous women with a singleton pregnancy at term, i.e. at least 36 weeks' completed gestation. We excluded trials that solely studied women whose labours were induced.

Interventions

Various different intravenous fluids in different volumes (see Effects of interventions below).

Excluded studies

We excluded 26 trials. For details, see Characteristics of excluded studies. In addition, we identified one trial that is still ongoing (Salim 2011) and two that are awaiting assessment (Amir 2004; Rad 2012).

Risk of bias in included studies

Summaries of risk of bias assessments have been set out in Figure 1 and Figure 2.

Figure 1.

'Risk of bias' graph: review authors' judgements about each risk of bias item presented as percentages across all included studies.

Figure 2.

'Risk of bias' summary: review authors' judgements about each risk of bias item for each included study.

Allocation

Adequate and secure concealment of allocation was described in seven trials (Coco 2010; Direkvand-Moghadam 2012; Eslamian 2006; Garite 2000; Kavitha 2012; Shrivastava 2009; Stratton 1995). We classified as unclear allocation risk in the Alavi 2005 trial, as although sealed envelopes were used there was unclear information on the method of randomisation. There was also an unclear risk of allocation concealment in the study by Maderia 2007 as it was published as an abstract with limited information.

Blinding

Where intravenous fluids were compared with no intravenous fluids, masking women and staff would not be feasible, and staff would also be likely to be aware of treatment group when women were randomised to have different rates of infusion. Lack of blinding may have had an effect on outcomes in five of the included studies (Alavi 2005; Coco 2010; Direkvand-Moghadam 2012; Garite 2000; Kavitha 2012). In one study it was stated that infusion rates were masked (Eslamian 2006), and in one study reported in a brief abstract, it was not clear whether there had been any attempt at blinding women and staff. Where different intravenous fluids were compared women and staff were blinded in Shrivastava 2009, but it was not clear whether there was blinding or not in Stratton 1995.

Incomplete outcome data

In most of our included studies all women were accounted for in the analysis, or rates of attrition were low, reasons for loss to follow-up were explained, and were balanced across groups. In the Coco 2010 study, women were recruited during pregnancy and there was a high rate of loss to follow- up, putting this study at high risk of bias for this domain.

Effects of interventions

For the sake of clarity we have used the following comparisons.

  • Intravenous fluid versus no intravenous fluids (restricted oral intake)

  • Intravenous fluids versus no intravenous fluids (unrestricted oral intake)

  • Intravenous fluids + oral intake versus intravenous fluids alone

  • Intravenous fluids + oral intake versus oral intake alone

  • Different rates of intravenous fluids + oral intake

  • Comparison of different rates of intravenous fluids

  • Comparison of different types of intravenous fluids

Three trials with more than two arms are included in more than one comparison (Direkvand-Moghadam 2012; Kavitha 2012; Shrivastava 2009).

Comparison 1: Intravenous fluid alone versus no intravenous fluids (restricted oral intake)

None of the included studies analysed this comparison.

Comparison 2: Intravenous fluids alone versus no intravenous fluids (unrestricted oral intake)

None of the included trials analysed this comparison.

Comparison 3: Intravenous fluids alone versus intravenous fluids and oral intake

None of the included studies studied this comparison

Comparison 4: Intravenous fluids (up to 250 mL/hour) + oral intake versus oral intake alone

Two trials were included in this comparison (Direkvand-Moghadam 2012; Kavitha 2012).

In the study by Direkvand-Moghadam 2012, 120 women were divided into four groups; the control group was allowed free oral intake of water and/or, soft drinks, in three intervention arms women received intravenous Ringer lactate solution at rates of 60 mL, 120 mL or 250 mL per hour throughout active labour and were also allowed free oral fluids. To allow a single pair-wise comparison for this study, in the data and analysis tables for this comparison, we combined the results for the three groups receiving intravenous fluids. The mean total amount of oral or intravenous intake for the four groups was not stated.

In Kavitha 2012, 96 women were randomised to receive 250 mL/hour of Ringer's lactate solution as well as oral intake, and 99 women received oral intake only. The mean amount of oral fluid intake was 1325 mL in the intravenous fluid group and 896 mL in the oral intake group. Oral intake included both plain water and coconut water.

Primary outcomes
Maternal outcomes

Duration of labour in minutes (vaginal deliveries): Both studies reported on the duration of labour although Direkvand-Moghadam 2012 reported separate results for each stage of labour and in the analysis we used the duration of the active first stage of labour. There was a reduction in the duration of labour in the intravenous fluids + oral intake group of 29 minutes (mean difference (MD) -28.86, 95% confidence interval (CI) -47.41 to -10.30, two studies, 241 women) (Analysis 4.1). Direkvand-Moghadam 2012 reported that the duration of the 2nd and the 3rd stages of labour were reduced for women receiving intravenous fluids, although the difference between groups for the third stage was not statistically significant (data not shown).

Mode of delivery: There was no statistically significant reduction in the number of caesarean sections (CS) in the intravenous fluid group (risk ratio (RR) 0.73, 95% CI 0.49 to1.08, two studies, 315 women) (Analysis 4.2). Neither study reported the number of assisted vaginal deliveries.

Fluid overload: There were no cases of fluid overload in either group in the Kavitha 2012 trial.

Neonatal outcomes

NICU admission: There was no evidence of a statistically significant difference in admission to the neonatal unit in the Kavitha 2012 trial (RR 0.52, 95% CI 0.05 to 5.59) (Analysis 4.5).

Apgar score > seven at five minutes: This was reported by Direkvand-Moghadam 2012; there were no infants with a low Apgar score at five minutes in either group (Analysis 4.6).

Other primary outcomes: Neither of the two studies included in this comparison reported on cord pH or newborn weight loss.

Secondary outcomes

There were no data reported for any of our maternal or infant secondary outcomes (maternal hyponatraemia, maternal comfort/discomfort, maternal feelings of thirst, neonatal hyponatraemia, neonatal hypoglycaemia or hyperbilirubinaemia).

Comparison 5: Intravenous fluids 125 mL/hour + oral intake versus intravenous fluids 250 mL/hour + oral intake

Three studies were included in this comparison (Coco 2010; Direkvand-Moghadam 2012; Kavitha 2012).

Primary outcomes
Maternal outcomes

Duration of labour in minutes (vaginal deliveries): All three studies included in this comparison reported on the duration of labour. (Direkvand-Moghadam 2012 reported separate results for each stage of labour and in the analysis we have used the length of the active first stage of labour). Women receiving a greater hourly volume of intravenous fluids (250 mL) plus free oral fluids had shorter labours than those receiving 125 mL (MD 23.87, 95% CI 3.72 to 44.02, three studies, 256 women) (Analysis 5.1).

Mode of delivery: There was no statistically significant reduction in the number of caesarean sections (CS) in the 250 mL hourly intravenous fluid group (average RR 1.00, 95% CI 0.54 to1.87, three studies, 334 women (random-effects analysis)) (Analysis 5.2). One study reported results for 80 women and the number of assisted vaginal deliveries was lower in the group receiving 125 mL hourly plus free oral fluids compared with the group receiving 250 mL although there were relatively high numbers of assisted deliveries in both groups in this study (RR 0.47, 95% CI 0.27 to 0.81) (Analysis 5.3).

Fluid overload: There were no cases of fluid overload in either group in the two studies reporting this outcome.

Neonatal outcomes

NICU admission: There was no strong evidence of a difference between groups in admission to the neonatal unit in the two trials reporting this outcome; overall, there were a total of eight admissions from the pooled sample of 274 (RR 0.56, 95% CI 0.15 to 2.06) (Analysis 5.5).

Apgar score > seven at five minutes: This was reported by Coco 2010 and Direkvand-Moghadam 2012; there were no infants with a low Apgar score at five minutes in either study (Analysis 5.6).

Other primary outcomes: None of the studies included in this comparison reported on cord pH or newborn weight loss.

Secondary outcomes

There were no data reported for any of our maternal or infant secondary outcomes (maternal hyponatraemia, maternal comfort/discomfort, maternal feelings of thirst, neonatal hyponatraemia, neonatal hypoglycaemia or hyperbilirubinaemia).

Comparison 6: Comparison of different rates of intravenous fluids (125 mL/hour versus 250 mL/hour) with restricted oral intake

Four trials (Alavi 2005; Eslamian 2006; Garite 2000; Maderia 2007 ) were included in this comparison with a total number of 808 women. Two trials (Eslamian 2006; Garite 2000 ) compared different rates of Ringer's lactate solution. The Alavi 2005 trial compared different rates of normal saline in dextrose water, while there was no further information on the type of fluid used in the Maderia 2007 trial.

Primary outcomes
Maternal outcomes

Duration of labour in minutes (vaginal deliveries): There was a significant reduction in the duration of labour in women who received a higher infusion rate of intravenous fluids (MD 105.61, 95% CI 53.19 to 158.02 (P < 0.0001) four studies, 632 women. However, findings must be interpreted with caution as results in the four trials were not consistent. There was fairly high statistical heterogeneity amongst trials and results have been pooled using a random-effects model (heterogeneity within this comparison I2 = 53%) (Analysis 6.1).

Mode of delivery: There was a significant reduction in the caesarean section rate in women receiving a higher rate of intravenous fluid infusion without any significant heterogeneity between trials (RR 1.56, 95% CI 1.10 to 2.21; (P = 0.01) four trials, 748 women, I2 = 0%) (Analysis 6.2).

Only two trials reported on assisted delivery (Eslamian 2006; Garite 2000). There was no evidence of any difference between groups in the assisted delivery rate (RR 0.78, 95% CI 0.44 to 1.40 (Analysis 6.3).

Fluid overload: Only one trial reported on fluid overload (Garite 2000). Only one woman in the 125 mL/hour group was reported to have developed fluid overload, while no women suffered this in the 250 mL/hour group (RR 3.22 and wide 95% CI of 0.13 to 78.11) (Analysis 6.4).

Neonatal outcomes

NICU admission: There was no strong evidence that the rate of infusion affected admission to NICU in 3 studies with data for 689 babies, overall the number of admissions was relatively low and results in different studies were not consistent. We used a random-effects model for this analyses and the 95% confidence intervals for this outcome are wide (average RR 0.48, 95% CI 0.07 to 3.17, I2 47%). (Analysis 6.5).

Apgar score < seven at five minutes: More babies had low Apgar scores in the 125 mL/hour group compared to the 250 mL/hour group although the difference between groups was not statistically significant (RR 4.35, 95% CI 0.97 to 19.51, three studies, 689 babies) (Analysis 6.6).

Other primary outcomes: Neither of the studies included in this comparison reported on cord pH or newborn weight loss.

Secondary outcomes

None of the trials reported on maternal feelings of thirst, maternal comfort or satisfaction/dissatisfaction of being attached to intravenous fluids. None of the trials reported on low cord pH, neonatal hyponatraemia, hypoglycaemia, fetal hyperbilirubinaemia or newborn weight loss.

Comparison 7: 125 mL/hour Ringer's lactate versus 125 mL/hour 5% dextrose

None of the trials included in this version of the review analysed this comparison.

Comparison 8: 125 mL/hour normal saline versus 125 mL/hour 5% dextrose

Two trials ( Shrivastava 2009) and Stratton 1995 analysed this comparison involving 284 women. In the Shrivastava 2009 trial, a total of 191 women were randomised to two groups: 97 women were randomised to receive 125 mL/hour normal saline and 94 women were randomised to receive 125 mL/hour of 5% dextrose solution. In the Stratton 1995 trial, 45 women received normal saline and 48 women received 5% dextrose solution.

Primary outcomes
Maternal outcomes

Duration of labour in minutes: Both studies included in this comparison reported duration of labour. Stratton 1995 reported the mean duration of labour and there was no strong evidence of a difference in the duration of labour for women receiving normal saline versus a 5% dextrose solution (MD of -12.00, 95% CI -30.09 to 6.09) (Analysis 8.1). Shrivastava 2009 reported the median time from fluid initiation to delivery and reported shorter duration in the 5% dextrose group (median 392 minutes) versus the normal saline group (median 464 minutes) and this difference between groups was reported to be statistically significant (P = 0.02) (data not shown in the data and analysis tables).

Mode of delivery: There was no significant difference in the need for caesarean section or assisted delivery (RR 0.77, 95% CI 0.41 to 1.43, two studies, 284 women) and (RR 0.59, 95% CI 0.21 to 1.63, one study, 93 women) respectively. (Analysis 8.2; Analysis 8.3).

Fluid overload: There were no cases of fluid overload in either group in the single study reporting this outcome (Analysis 8.4.)

Neonatal outcomes

NICU admission: There was no evidence of a difference between groups in admissions to the neonatal unit (RR 1.11, 95% CI 0.42 to 2.93, two studies, 284 babies) (Analysis 8.5).

Apgar score < seven at five minutes: There was no difference in the number of babies with low Apgar scores (RR 0.48, 95% CI 0.04, 5.25, two studies, 284 babies) (Analysis 8.6).

Other primary outcomes: Neither of the two studies included in this comparison reported on cord pH or newborn weight loss.

Secondary outcomes

As far as maternal complications are concerned, only the Stratton 1995 trial reported on maternal hyponatraemia (serum sodium levels < 135 mmol/L ). While none of the women in the normal saline group developed hyponatraemia, nine women in the dextrose groups did (RR 0.06, 95% CI 0.00, 0.94) (Analysis 8.9). The Shrivastava 2009 trial did not conduct any assessment of maternal hyponatraemia. (This was not a pre-specified review outcome.)

In the Stratton 1995 trial, one-third of babies (33.3%) developed hyponatraemia in the dextrose group compared to 13.3 % in the normal saline group (RR 0.40, 95% CI 0.17 to 0.93; P = 0.03) (Analysis 8.12). It is noteworthy that the Shrivastava 2009 trial did not conduct any testing for neonatal hyponatraemia. The Shrivastava 2009 trial did report neonatal hyperbilirubinaemia, and although there were more babies in the dextrose group of babies with hyperbilirubinaemia the difference between groups was not statistically significant (RR 0.39, 95% CI 0.08 to 1.95) (Analysis 8.13). There was no difference in neonatal hypoglycaemic episodes between the two groups with a RR of 0.97, (95% CI 0.20 to 4.68) (Analysis 8.14).

Comparison 9: 125 mL/hour normal saline versus 125 mL/hour Ringer's lactate

None of the included trials so far have analysed this comparison.

Discussion

We reviewed nine trials that collectively recruited 1781 women. However, due to attrition and various exclusion factors, the final analysis is based on 1617 women.

One of the underlining objectives of this review was to determine, in the first instance whether or not, the routine administration of intravenous fluids conferred any benefit to nulliparous labouring women, particularly in reducing the duration of labour. Therefore, we searched for trials that compared "usual care" of unrestricted oral fluids with intravenous fluid administration. Only two trials analysed this comparison (Direkvand-Moghadam 2012; Kavitha 2012). Pooled results from these trials showed a reduction in mean duration of labour for women receiving intravenous fluids compared with oral intake only. However, it is worth noting that in one of the trials (Kavitha 2012), the mean oral intake in the women in the intravenous fluids + oral intake group was much higher than in the oral intake group only (1325 versus 896 mL). There were no significant maternal or neonatal complications in the intravenous fluids group. As these findings are based on just two trials, they need to be interpreted with caution.

In the Coco 2010 trial, women were divided into two groups, i.e. intravenous fluids and oral intake versus "usual care", the "usual care" that was referred to was not confined solely to oral intake. In fact, women in the "usual care" group had received a mean volume of 1627 mL of intravenous fluid (approximating to a rate of 125 mL/hour). The intravenous fluid that was administered in both groups was Ringer's lactate. The findings of the Coco 2010 trial were therefore grouped with the comparison of 125 mL/hour of intravenous fluid and oral intake versus 250 mL/hour intravenous fluid and oral intake. Two groups from the Kavitha 2012 and Direkvand-Moghadam 2012 trials also compared these different rates. The findings from these trials showed a reduction in the duration of labour in the 250 mL/hour intravenous fluid + oral intake group.There was a difference in the types of oral fluids that were consumed in two of these trials. In the Kavitha 2012 trial the oral fluid intake consisted of plain water and coconut water, while in the Coco 2010 trial, oral intake included water, juices and carbonated drinks, and these may have influenced calorific content. The quality of the Coco 2010 trial needs to be taken into account as although the trial initially recruited 220 women, there was a very high attrition rate with more than 60% of women excluded from the final analysis, which was based on only 80 participants.

The main drive for routine intravenous fluid administration, was as a consequence of the pervasive 'nil by mouth' policy for labouring women. The justification and arguments against this has been addressed above. As such, intravenous fluids are administered to women in labour without robust scientific evidence that they are required, or if they are required, what volumes or which types of fluids are to be used. An arbitrary rate of 125 mL/hour seems to be employed by many centres. Hence, our next question was to determine whether when women are restricted in their oral intake, and intravenous fluids are administered, is the rate of 125 mL/hour sufficient?

Four trials (Alavi 2005; Eslamian 2006; Garite 2000; Maderia 2007), in which women were restricted in their oral intake, compared 125 mL/hour versus 250 mL/hour of intravenous fluids.The type of fluid in the Alavi 2005 trial was normal saline in dextrose water. Both the Eslamian 2006 and Garite 2000 trials administered Ringer's lactate solution. There was insufficient information on the type of fluid that was used in the Maderia 2007 trial as it was published as an abstract only. The meta-analysis of the four trials revealed that the mean duration of labour was significantly reduced (by approximately one and half hours) in the group that received the increased rate of 250 mL/hour of fluid, however there was considerable heterogeneity between trials which makes this result more difficult to interpret. In addition, there was a statistically significant reduction in the number of caesarean sections in the 250 mL/hour group. There was insufficient information about the indication for CS in the Maderia 2007 trial, however, the remaining three trials (Alavi 2005; Eslamian 2006; Garite 2000) describe the indication for CS, and the majority of CS were for failure to progress in the first stage. What was not standardised however, is how "failure to progress" was diagnosed in each of the trials. None of the trials was able to demonstrate conclusively that increased hydration directly prevented caesarean sections for failure to progress.There was no significant difference in the rates of assisted delivery between the two groups. As far as neonatal complications were concerned, more babies were admitted to the neonatal unit in the 250 mL/hour group, although the difference between groups was not statistically significant. However, there was a statistically higher risk of low Apgar scores in the 250 mL/hour group. None of the trials reported on neonatal hyponatraemia, hypoglycaemia or newborn weight loss in the first three days of life.

The impact on maternal and neonatal safety of different types of intravenous fluids has not been rigorously evaluated. The three most common solutions that are used are normal saline, Ringer's lactate and dextrose solutions. None of the trials directly compared normal saline versus Ringer's lactate, or Ringers' lactate versus dextrose solutions. Two trials Shrivastava 2009; Stratton 1995 compared normal saline versus 5% dextrose solution. The Shrivastava 2009 trial administered the same rate of 125 mL/hour for both solutions. Although the Stratton 1995 trial also administered the same rate of fluids in their two groups, the rate was not the same as the Shrivastava 2009 trial. The results of these two trials were not consistent in Stratton 1995 there were no clear differences in the mean duration of labour, whereas Shrivastava 2009 reported shorter duration in the 5% dextrose group (reported as median). There was no difference in the rates of caesarean section or assisted delivery between the two groups. Regarding maternal complications, the Shrivastava 2009 trial did not assess for maternal hyponatraemia. Based on just the Stratton 1995 trial, there was a statistically significant increased risk of maternal hyponatraemia noted in the dextrose group. There was no assessment of fluid overload in the Shrivastava 2009 trial, and there were no cases of fluid overload in either group in the Stratton 1995 trial. Regarding neonatal welfare, there was no difference in the admission to SCBU or low Apgar scores between the groups. While the Shrivastava 2009 trial did not report on neonatal hyponatraemia, the Stratton 1995 trial found a statistically higher incidence of neonatal hyponatraemia in the dextrose arm of the trial.

In summary, the routine administration of intravenous fluids compared with oral intake alone demonstrated that intravenous fluids conferred a reduction in the duration of labour, however, this was based on limited evidence. The findings of the other trials in this review suggest that if a policy of strictly no oral intake is to be employed, then the duration of labour in nulliparous women may be shortened by the administration of intravenous fluids at a rate of 250 mL/hour rather than 125 mL/hour. The caesarean section rate may also be reduced. However, is it justifiable to subject women to routine intravenous fluids for a reduction in the labour when it is not clear that this would have a positive effect on other maternal and neonatal outcomes? There are inconsistencies across the trials with regard to maternal and neonatal adverse outcome and several trials have simply not reported on the safety of increased intravenous fluids.

Of concern too, is the increased attendant maternal and neonatal morbidity that is associated with intravenous 5% dextrose solutions. Both maternal and neonatal hyponatraemia are increased, and although these results are based on just one trial, perhaps 5% dextrose should be avoided until a larger trial can demonstrate better safety.

None of the trials that were included in this review reported on the evaluation of maternal views of comfort, satisfaction or dissatisfaction of being attached to a drip during their entire labour. Furthermore, there was no subjective or objective evaluation of maternal thirst. There was no objective assessment of dehydration either (no measurements of ketosis). None of the trials elicited whether or not there is any associated newborn weight loss with intravenous fluids.

Quality of the evidence

Overall, the quality of evidence in this review is limited: firstly, for any one outcome few studies contributed results, and for many outcomes evidence was derived from only one or two relatively small trials. Furthermore, for our primary outcome results were not simple to interpret. Duration of labour was not measured in a consistent way between trials; in some studies duration was from the initiation of study fluids to delivery, while in others it was for a specific stage of labour and the total duration was not stated. One study reported the median (Shrivastava 2009), and for studies reporting the mean the standard deviation (SD) was frequently not reported. For these studies, to allow us to include the data, we calculated the SD from other information in the paper. As the mean was reported in most studies, we assumed that the distribution was normal and that the SD was similar in both arms of the trials, but this was not always clear. In addition, not all studies made it clear that the duration of labour related only to those women having vaginal deliveries; in the studies by Alavi 2005 and Kavitha 2012 for example, this was not explicitly stated. In the data and analysis we have used the number of women having vaginal deliveries as the denominators. The findings of the review also need to be interpreted in the light of our assessments of risk of bias; overall, the methodological quality of studies was assessed as moderate or good, but for some bias domains we were unable to make judgements about bias due to unclear descriptions, or limited descriptions of the methods used.

Authors' conclusions

Implications for practice

In the first instance, taking into account the potential maternal and neonatal morbidity that may arise from the unnecessary administration of intravenous fluids, we need to justify why the policy of 'nil by mouth' still permeates current practice. This is especially so since the dangers of gastric aspiration have been shown to be virtually eliminated and a concern of the past. Therefore, given that there is no clear evidence of harm associated with unrestricted oral intake perhaps it is time to abandon this policy altogether and to allow women to self-regulate their oral intake during labour. Rather than routine administration of intravenous fluids, it may be more appropriate for intravenous fluids to be administered for clinical reasons, or if a labouring women becomes ketotic.

The evidence gleaned from this review does not provide evidence that is robust enough to recommend routine administration of intravenous fluids. Interpreting findings relating to duration of labour was not straightforward as there was considerable heterogeneity in terms of the mean length of labour and in the variability in length of labour (SDs) in different trials. It is unclear why duration of labour was so different in the various settings but this may partly be explained by different definitions of the start of active labour. There was also variation in the rates of CS and assisted deliveries in different settings.

In addition, interpreting the results from trials was hampered by the low number of trials contributing data to each comparison and in variation between trials. In trials where oral fluids were not restricted there was considerable variation in the amount of oral fluid women consumed in different arms of the same trial as well as between different trials. In addition, results from trials were not consistent and the risk of bias in trials varied. Some of the important research questions were addressed by single trials only and important outcomes relating to maternal and infant morbidity were frequently not reported.

Implications for research

The findings of these trials do have clinical implications for labour management, however, more studies are needed to validate these findings and to elicit a scientific evaluation to quantify levels of hydration in labouring women. Perhaps an objective assessment of maternal dehydration may improve the quality of future studies.

Further trials are also required to evaluate whether additional intravenous fluids in women with unlimited access to oral fluids confers any reduction in the length of labour, without potentially harming the neonate. Future trials should definitely also include an evaluation of maternal perceptions, comfort and mobility during labour.

Since there is emerging evidence that excessive intravenous fluids may cause newborn weight loss in the first 72 hours, future trials should attempt to elicit this. More high quality trials need to be conducted that address whether there is even a need for intravenous fluids at all.

Acknowledgements

Sincere gratitude to Lynn Hampson and Frances Kellie for their guidance and assistance in trial searches and methodology.

As part of the pre-publication editorial process, this review has been commented on by three peers (an editor and two referees who are external to the editorial team) and the Group's Statistical Adviser.

The National Institute for Health Research (NIHR) is the largest single funder of the Cochrane Pregnancy and Childbirth Group. The views and opinions expressed therein are those of the authors and do not necessarily reflect those of the NIHR, NHS or the Department of Health.

The final version of this systematic review was financially supported by the UNDP-UNFPA-UNICEF-WHO-World Bank Special Programme of Research, Development and Research Training in Human Reproduction (HRP) and the Department of Reproductive Health and Research (RHR), World Health Organization. The named authors alone are responsible for the views expressed in this publication.

Data and analyses

Download statistical data

Comparison 1. Intravenous fluids versus no fluids (restricted oral intake)
Outcome or subgroup titleNo. of studiesNo. of participantsStatistical methodEffect size
1 Mean duration of labour in minutes00Mean Difference (IV, Fixed, 95% CI)0.0 [0.0, 0.0]
2 Caesarean section00Risk Ratio (M-H, Fixed, 95% CI)0.0 [0.0, 0.0]
3 Assisted delivery00Risk Ratio (M-H, Fixed, 95% CI)0.0 [0.0, 0.0]
4 Maternal hyponatraemia (sodium level < 135 mmol/L)00Risk Ratio (M-H, Fixed, 95% CI)0.0 [0.0, 0.0]
5 Fluid overload00Risk Ratio (M-H, Fixed, 95% CI)0.0 [0.0, 0.0]
6 Subjective feelings of thirst00Risk Ratio (M-H, Fixed, 95% CI)0.0 [0.0, 0.0]
7 Maternal comfort/satisfaction00Risk Ratio (M-H, Fixed, 95% CI)0.0 [0.0, 0.0]
8 Admission to neonatal unit00Risk Ratio (M-H, Fixed, 95% CI)0.0 [0.0, 0.0]
9 Low Apgar scores (< 7 at 5 mins)00Risk Ratio (M-H, Fixed, 95% CI)0.0 [0.0, 0.0]
10 Cord pH < 7.000Risk Ratio (M-H, Fixed, 95% CI)0.0 [0.0, 0.0]
11 Neonatal hyponatraemia (cord sodium level < 135 mmol/L)00Mean Difference (IV, Fixed, 95% CI)0.0 [0.0, 0.0]
12 Neonatal hypoglycaemia00Risk Ratio (M-H, Fixed, 95% CI)0.0 [0.0, 0.0]
13 Fetal hyperbilirubinaemia00Risk Ratio (M-H, Fixed, 95% CI)0.0 [0.0, 0.0]
14 Newborn weight loss( first 72 hours)00Risk Ratio (M-H, Fixed, 95% CI)0.0 [0.0, 0.0]
Comparison 2. Intravenous fluids alone versus no intravenous fluids (unrestricted oral intake
Outcome or subgroup titleNo. of studiesNo. of participantsStatistical methodEffect size
1 Mean duration of labour00Mean Difference (IV, Fixed, 95% CI)0.0 [0.0, 0.0]
2 Caesarean section00Risk Ratio (M-H, Fixed, 95% CI)0.0 [0.0, 0.0]
3 Assisted delivery00Risk Ratio (M-H, Fixed, 95% CI)0.0 [0.0, 0.0]
4 Fluid overload or pulmonary oedema00Risk Ratio (M-H, Fixed, 95% CI)0.0 [0.0, 0.0]
5 Maternal hyponatraemia (sodium level < 135 mmol/L)00Risk Ratio (M-H, Fixed, 95% CI)0.0 [0.0, 0.0]
6 Subjective feelings of thirst00Risk Ratio (M-H, Fixed, 95% CI)0.0 [0.0, 0.0]
7 Maternal comfort/satisfaction00Risk Ratio (M-H, Fixed, 95% CI)0.0 [0.0, 0.0]
8 Admission to neonatal unit00Risk Ratio (M-H, Fixed, 95% CI)0.0 [0.0, 0.0]
9 Low Apgar scores (< 7 at 5 mins)00Risk Ratio (M-H, Fixed, 95% CI)0.0 [0.0, 0.0]
10 Cord pH < 7.000Risk Ratio (M-H, Fixed, 95% CI)0.0 [0.0, 0.0]
11 Neonatal hyponatraemia (cord sodium level < 135 mmol/L)00Mean Difference (IV, Fixed, 95% CI)0.0 [0.0, 0.0]
12 Neonatal hypoglycaemia00Risk Ratio (M-H, Fixed, 95% CI)0.0 [0.0, 0.0]
13 Fetal hyperbilirubinaemia00Risk Ratio (M-H, Fixed, 95% CI)0.0 [0.0, 0.0]
14 Newborn weight loss( first 72 hours)00Risk Ratio (M-H, Fixed, 95% CI)0.0 [0.0, 0.0]
Comparison 3. Intravenous fluids alone versus intravenous fluids and oral intake
Outcome or subgroup titleNo. of studiesNo. of participantsStatistical methodEffect size
1 Mean duration of labour in minutes00Mean Difference (IV, Fixed, 95% CI)0.0 [0.0, 0.0]
2 Caesarean section00Risk Ratio (M-H, Fixed, 95% CI)0.0 [0.0, 0.0]
3 Assisted delivery00Risk Ratio (M-H, Fixed, 95% CI)0.0 [0.0, 0.0]
4 Maternal hyponatraemia (sodium level < 135 mmol/L)00Risk Ratio (M-H, Fixed, 95% CI)0.0 [0.0, 0.0]
5 Fluid overload00Risk Ratio (M-H, Fixed, 95% CI)0.0 [0.0, 0.0]
6 Subjective feelings of thirst00Risk Ratio (M-H, Fixed, 95% CI)0.0 [0.0, 0.0]
7 Maternal comfort/satisfaction00Risk Ratio (M-H, Fixed, 95% CI)0.0 [0.0, 0.0]
8 Admission to neonatal unit00Risk Ratio (M-H, Fixed, 95% CI)0.0 [0.0, 0.0]
9 Low Apgar scores (< 7 at 5 mins)00Risk Ratio (M-H, Fixed, 95% CI)0.0 [0.0, 0.0]
10 Cord pH < 7.000Risk Ratio (M-H, Fixed, 95% CI)0.0 [0.0, 0.0]
11 Neonatal hyponatraemia (cord sodium level < 135 mmol/L)00Mean Difference (IV, Fixed, 95% CI)0.0 [0.0, 0.0]
12 Neonatal hypoglycaemia00Risk Ratio (M-H, Fixed, 95% CI)0.0 [0.0, 0.0]
13 Fetal hyperbilirubinaemia00Risk Ratio (M-H, Fixed, 95% CI)0.0 [0.0, 0.0]
14 Newborn weight loss (first 72 hours)00Risk Ratio (M-H, Fixed, 95% CI)0.0 [0.0, 0.0]
Comparison 4. Intravenous fluids + oral intake versus oral intake alone
Outcome or subgroup titleNo. of studiesNo. of participantsStatistical methodEffect size
1 Mean duration of labour2241Mean Difference (IV, Fixed, 95% CI)-28.86 [-47.41, -10.30]
2 Caesarean section2315Risk Ratio (M-H, Fixed, 95% CI)0.73 [0.49, 1.08]
3 Assisted delivery00Risk Ratio (M-H, Fixed, 95% CI)0.0 [0.0, 0.0]
4 Fluid overload1195Risk Ratio (M-H, Fixed, 95% CI)0.0 [0.0, 0.0]
5 Admission to neonatal unit1195Risk Ratio (M-H, Fixed, 95% CI)0.52 [0.05, 5.59]
6 Low Apgar scores (< 7 at 5 mins)1120Risk Ratio (M-H, Fixed, 95% CI)0.0 [0.0, 0.0]
7 Cord pH < 7.000Risk Ratio (M-H, Fixed, 95% CI)0.0 [0.0, 0.0]
8 Newborn weight loss (first 72 hours)00Risk Ratio (M-H, Fixed, 95% CI)0.0 [0.0, 0.0]
9 Maternal hyponatraemia (sodium level < 135 mmol/L)00Risk Ratio (M-H, Fixed, 95% CI)0.0 [0.0, 0.0]
10 Subjective feelings of thirst00Risk Ratio (M-H, Fixed, 95% CI)0.0 [0.0, 0.0]
11 Maternal comfort/satisfaction00Risk Ratio (M-H, Fixed, 95% CI)0.0 [0.0, 0.0]
12 Neonatal hyponatraemia (cord sodium level < 135 mmol/L)00Mean Difference (IV, Fixed, 95% CI)0.0 [0.0, 0.0]
13 Neonatal hypoglycaemia00Risk Ratio (M-H, Fixed, 95% CI)0.0 [0.0, 0.0]
14 Fetal hyperbilirubinaemia00Risk Ratio (M-H, Fixed, 95% CI)0.0 [0.0, 0.0]
Analysis 4.1.

Comparison 4 Intravenous fluids + oral intake versus oral intake alone, Outcome 1 Mean duration of labour.

Analysis 4.2.

Comparison 4 Intravenous fluids + oral intake versus oral intake alone, Outcome 2 Caesarean section.

Analysis 4.4.

Comparison 4 Intravenous fluids + oral intake versus oral intake alone, Outcome 4 Fluid overload.

Analysis 4.5.

Comparison 4 Intravenous fluids + oral intake versus oral intake alone, Outcome 5 Admission to neonatal unit.

Analysis 4.6.

Comparison 4 Intravenous fluids + oral intake versus oral intake alone, Outcome 6 Low Apgar scores (< 7 at 5 mins).

Comparison 5. 125 mL/hour intravenous fluids + oral intake versus 250 mL/hour intravenous fluids + oral intake
Outcome or subgroup titleNo. of studiesNo. of participantsStatistical methodEffect size
1 Mean duration of labour in minutes3256Mean Difference (IV, Fixed, 95% CI)23.87 [3.72, 44.02]
2 Caesarean section3334Risk Ratio (M-H, Random, 95% CI)1.00 [0.54, 1.87]
3 Assisted delivery180Risk Ratio (M-H, Fixed, 95% CI)0.47 [0.27, 0.81]
4 Fluid overload2274Risk Ratio (M-H, Fixed, 95% CI)0.0 [0.0, 0.0]
5 Admission to neonatal unit2274Risk Ratio (M-H, Fixed, 95% CI)0.56 [0.15, 2.06]
6 Low Apgar scores (< 7 at 5 mins)2140Risk Ratio (M-H, Fixed, 95% CI)0.0 [0.0, 0.0]
7 Cord pH < 7.000Risk Ratio (M-H, Fixed, 95% CI)0.0 [0.0, 0.0]
8 Newborn weight loss (first 72 hours)00Risk Ratio (M-H, Fixed, 95% CI)0.0 [0.0, 0.0]
9 Maternal hyponatraemia (sodium level < 135 mmol/L)00Risk Ratio (M-H, Fixed, 95% CI)0.0 [0.0, 0.0]
10 Subjective feelings of thirst00Risk Ratio (M-H, Fixed, 95% CI)0.0 [0.0, 0.0]
11 Maternal comfort/satisfaction00Risk Ratio (M-H, Fixed, 95% CI)0.0 [0.0, 0.0]
12 Neonatal hyponatraemia (cord sodium level < 135 mmol/L)00Mean Difference (IV, Fixed, 95% CI)0.0 [0.0, 0.0]
13 Neonatal hypoglycaemia00Risk Ratio (M-H, Fixed, 95% CI)0.0 [0.0, 0.0]
14 Fetal hyperbilirubinaemia00Risk Ratio (M-H, Fixed, 95% CI)0.0 [0.0, 0.0]
Analysis 5.1.

Comparison 5 125 mL/hour intravenous fluids + oral intake versus 250 mL/hour intravenous fluids + oral intake, Outcome 1 Mean duration of labour in minutes.

Analysis 5.2.

Comparison 5 125 mL/hour intravenous fluids + oral intake versus 250 mL/hour intravenous fluids + oral intake, Outcome 2 Caesarean section.

Analysis 5.3.

Comparison 5 125 mL/hour intravenous fluids + oral intake versus 250 mL/hour intravenous fluids + oral intake, Outcome 3 Assisted delivery.

Analysis 5.4.

Comparison 5 125 mL/hour intravenous fluids + oral intake versus 250 mL/hour intravenous fluids + oral intake, Outcome 4 Fluid overload.

Analysis 5.5.

Comparison 5 125 mL/hour intravenous fluids + oral intake versus 250 mL/hour intravenous fluids + oral intake, Outcome 5 Admission to neonatal unit.

Analysis 5.6.

Comparison 5 125 mL/hour intravenous fluids + oral intake versus 250 mL/hour intravenous fluids + oral intake, Outcome 6 Low Apgar scores (< 7 at 5 mins).

Comparison 6. 125 mL/hour fluids versus 250 mL/hour fluids (restricted oral intake in both arms)
Outcome or subgroup titleNo. of studiesNo. of participantsStatistical methodEffect size
1 Mean duration of labour in minutes4632Mean Difference (IV, Random, 95% CI)105.61 [53.19, 158.02]
2 Caesarean section4748Risk Ratio (M-H, Fixed, 95% CI)1.56 [1.10, 2.21]
3 Assisted delivery2495Risk Ratio (M-H, Fixed, 95% CI)0.78 [0.44, 1.40]
4 Fluid overload1195Risk Ratio (M-H, Fixed, 95% CI)3.22 [0.13, 78.11]
5 Admission to neonatal unit3689Risk Ratio (M-H, Random, 95% CI)0.48 [0.07, 3.17]
6 Low Apgar scores (< 7 at 5 mins)3689Risk Ratio (M-H, Fixed, 95% CI)4.35 [0.97, 19.51]
7 Cord pH < 7.000Risk Ratio (M-H, Fixed, 95% CI)0.0 [0.0, 0.0]
8 Newborn weight loss (first 72 hours)00Risk Ratio (M-H, Fixed, 95% CI)0.0 [0.0, 0.0]
9 Maternal hyponatraemia (sodium level < 135 mmol/L)00Risk Ratio (M-H, Fixed, 95% CI)0.0 [0.0, 0.0]
10 Subjective feelings of thirst00Risk Ratio (M-H, Fixed, 95% CI)0.0 [0.0, 0.0]
11 Maternal comfort/satisfaction00Risk Ratio (M-H, Fixed, 95% CI)0.0 [0.0, 0.0]
12 Neonatal hyponatraemia (cord sodium level < 135 mmol/L)00Mean Difference (IV, Fixed, 95% CI)0.0 [0.0, 0.0]
13 Neonatal hypoglycaemia00Risk Ratio (M-H, Fixed, 95% CI)0.0 [0.0, 0.0]
14 Fetal hyperbilirubinaemia00Risk Ratio (M-H, Fixed, 95% CI)0.0 [0.0, 0.0]
Analysis 6.1.

Comparison 6 125 mL/hour fluids versus 250 mL/hour fluids (restricted oral intake in both arms), Outcome 1 Mean duration of labour in minutes.

Analysis 6.2.

Comparison 6 125 mL/hour fluids versus 250 mL/hour fluids (restricted oral intake in both arms), Outcome 2 Caesarean section.

Analysis 6.3.

Comparison 6 125 mL/hour fluids versus 250 mL/hour fluids (restricted oral intake in both arms), Outcome 3 Assisted delivery.

Analysis 6.4.

Comparison 6 125 mL/hour fluids versus 250 mL/hour fluids (restricted oral intake in both arms), Outcome 4 Fluid overload.

Analysis 6.5.

Comparison 6 125 mL/hour fluids versus 250 mL/hour fluids (restricted oral intake in both arms), Outcome 5 Admission to neonatal unit.

Analysis 6.6.

Comparison 6 125 mL/hour fluids versus 250 mL/hour fluids (restricted oral intake in both arms), Outcome 6 Low Apgar scores (< 7 at 5 mins).

Comparison 7. 125 mL/hour Ringer's lactate versus 125 mL/hour versus 5% dextrose
Outcome or subgroup titleNo. of studiesNo. of participantsStatistical methodEffect size
1 Mean duration of labour in minutes00Mean Difference (IV, Fixed, 95% CI)0.0 [0.0, 0.0]
2 Caesarean section00Risk Ratio (M-H, Fixed, 95% CI)0.0 [0.0, 0.0]
3 Assisted delivery00Risk Ratio (M-H, Fixed, 95% CI)0.0 [0.0, 0.0]
4 Fluid overload00Risk Ratio (M-H, Fixed, 95% CI)0.0 [0.0, 0.0]
5 Admission to neonatal unit00Risk Ratio (M-H, Fixed, 95% CI)0.0 [0.0, 0.0]
6 Low Apgar scores (< 7 at 5 mins)00Risk Ratio (M-H, Fixed, 95% CI)0.0 [0.0, 0.0]
7 Cord pH < 7.000Risk Ratio (M-H, Fixed, 95% CI)0.0 [0.0, 0.0]
8 Newborn weight loss (first 72 hours)00Risk Ratio (M-H, Fixed, 95% CI)0.0 [0.0, 0.0]
9 Maternal hyponatraemia (sodium level < 135 mmol/L)00Risk Ratio (M-H, Fixed, 95% CI)0.0 [0.0, 0.0]
10 Subjective feelings of thirst00Risk Ratio (M-H, Fixed, 95% CI)0.0 [0.0, 0.0]
11 Maternal comfort/satisfaction00Risk Ratio (M-H, Fixed, 95% CI)0.0 [0.0, 0.0]
12 Neonatal hyponatraemia (cord sodium level < 135 mmol/L)00Mean Difference (IV, Fixed, 95% CI)0.0 [0.0, 0.0]
13 Neonatal hypoglycaemia00Risk Ratio (M-H, Fixed, 95% CI)0.0 [0.0, 0.0]
14 Fetal hyperbilirubinaemia00Risk Ratio (M-H, Fixed, 95% CI)0.0 [0.0, 0.0]
Comparison 8. Normal saline versus 5% dextrose solutions
Outcome or subgroup titleNo. of studiesNo. of participantsStatistical methodEffect size
1 Mean duration of labour in minutes191Mean Difference (IV, Random, 95% CI)-12.0 [-30.09, 6.09]
2 Caesarean section2284Risk Ratio (M-H, Fixed, 95% CI)0.77 [0.41, 1.43]
3 Assisted delivery193Risk Ratio (M-H, Fixed, 95% CI)0.59 [0.21, 1.63]
4 Fluid overload193Risk Ratio (M-H, Fixed, 95% CI)0.0 [0.0, 0.0]
5 Admission to neonatal unit2284Risk Ratio (M-H, Fixed, 95% CI)1.11 [0.42, 2.93]
6 Low Apgar scores (< 7 at 5 mins)2284Risk Ratio (M-H, Random, 95% CI)0.48 [0.04, 5.25]
7 Cord pH < 7.000Risk Ratio (M-H, Fixed, 95% CI)0.0 [0.0, 0.0]
8 Newborn weight loss (first 72 hours)00Risk Ratio (M-H, Fixed, 95% CI)0.0 [0.0, 0.0]
9 Maternal hyponatraemia (sodium level < 135 mmol/L)191Risk Ratio (M-H, Fixed, 95% CI)0.06 [0.00, 0.94]
10 Subjective feelings of thirst00Risk Ratio (M-H, Fixed, 95% CI)0.0 [0.0, 0.0]
11 Maternal comfort/satisfaction00Risk Ratio (M-H, Fixed, 95% CI)0.0 [0.0, 0.0]
12 Neonatal hyponatraemia (cord sodium level < 135 mmol/L)193Risk Ratio (M-H, Fixed, 95% CI)0.4 [0.17, 0.93]
13 Neonatal hyperbilirubinaemia1191Risk Ratio (M-H, Fixed, 95% CI)0.39 [0.08, 1.95]
14 Neonatal hypoglycaemia (< 40 mg/dL)1191Risk Ratio (M-H, Fixed, 95% CI)0.97 [0.20, 4.68]
Analysis 8.1.

Comparison 8 Normal saline versus 5% dextrose solutions, Outcome 1 Mean duration of labour in minutes.

Analysis 8.2.

Comparison 8 Normal saline versus 5% dextrose solutions, Outcome 2 Caesarean section.

Analysis 8.3.

Comparison 8 Normal saline versus 5% dextrose solutions, Outcome 3 Assisted delivery.

Analysis 8.4.

Comparison 8 Normal saline versus 5% dextrose solutions, Outcome 4 Fluid overload.

Analysis 8.5.

Comparison 8 Normal saline versus 5% dextrose solutions, Outcome 5 Admission to neonatal unit.

Analysis 8.6.

Comparison 8 Normal saline versus 5% dextrose solutions, Outcome 6 Low Apgar scores (< 7 at 5 mins).

Analysis 8.9.

Comparison 8 Normal saline versus 5% dextrose solutions, Outcome 9 Maternal hyponatraemia (sodium level < 135 mmol/L).

Analysis 8.12.

Comparison 8 Normal saline versus 5% dextrose solutions, Outcome 12 Neonatal hyponatraemia (cord sodium level < 135 mmol/L).

Analysis 8.13.

Comparison 8 Normal saline versus 5% dextrose solutions, Outcome 13 Neonatal hyperbilirubinaemia.

Analysis 8.14.

Comparison 8 Normal saline versus 5% dextrose solutions, Outcome 14 Neonatal hypoglycaemia (< 40 mg/dL).

Comparison 9. 125 mL normal saline versus 125 mL Ringer's lactate
Outcome or subgroup titleNo. of studiesNo. of participantsStatistical methodEffect size
1 Mean duration of labour in minutes00Mean Difference (IV, Fixed, 95% CI)0.0 [0.0, 0.0]
2 Caesarean section00Risk Ratio (M-H, Fixed, 95% CI)0.0 [0.0, 0.0]
3 Assisted delivery00Risk Ratio (M-H, Fixed, 95% CI)0.0 [0.0, 0.0]
4 Maternal hyponatraemia (sodium level < 135 mmol/L)00Risk Ratio (M-H, Fixed, 95% CI)0.0 [0.0, 0.0]
5 Fluid overload00Risk Ratio (M-H, Fixed, 95% CI)0.0 [0.0, 0.0]
6 Subjective feelings of thirst00Risk Ratio (M-H, Fixed, 95% CI)0.0 [0.0, 0.0]
7 Maternal comfort/satisfaction00Risk Ratio (M-H, Fixed, 95% CI)0.0 [0.0, 0.0]
8 Admission to neonatal unit00Risk Ratio (M-H, Fixed, 95% CI)0.0 [0.0, 0.0]
9 Low Apgar scores (< 7 at 5 mins)00Risk Ratio (M-H, Fixed, 95% CI)0.0 [0.0, 0.0]
10 Cord pH < 7.000Risk Ratio (M-H, Fixed, 95% CI)0.0 [0.0, 0.0]
11 Neonatal hyponatraemia (cord sodium level < 135 mmol/L)00Mean Difference (IV, Fixed, 95% CI)0.0 [0.0, 0.0]
12 Neonatal hypoglycaemia00Risk Ratio (M-H, Fixed, 95% CI)0.0 [0.0, 0.0]
13 Fetal hyperbilirubinaemia00Risk Ratio (M-H, Fixed, 95% CI)0.0 [0.0, 0.0]
14 Newborn weight loss (first 72 hours)00Risk Ratio (M-H, Fixed, 95% CI)0.0 [0.0, 0.0]

Contributions of authors

Feroza Dawood (FD) created the first draft of the protocol and Siobhan Quenby (SQ) commented on the draft and suggested changes. FD, Therese Dowswell (TD) and SQ then analysed the data and drew up the final results. FD wrote the initial draft of the review and TD and SQ edited the review.

Declarations of interest

None known.

Sources of support

Internal sources

  • The University of Liverpool, UK.

External sources

  • UNDP-UNFPA-UNICEF-WHO-World Bank Special Programme of Research, Development and Research Training in Human Reproduction (HRP) and the Department of Reproductive Health and Research (RHR), World Health Organization, Switzerland.

Differences between protocol and review

'Apgar score less than seven at five minutes' has been added as a fetal and neonatal secondary outcome.

'Early newborn weight loss' has been removed from the list of fetal and neonatal secondary outcomes.

Characteristics of studies

Characteristics of included studies [ordered by study ID]

Alavi 2005

MethodsProspective randomised clinical trial.
Participants

194 nulliparous women in term spontaneous labours with a singleton pregnancy, cephalic presentation.

112 women received 125 mL/hour; 82 women received 250 mL/hour.

Interventions125 mL/hour vs 250 mL/hour of normal saline in dextrose water.
OutcomesDuration of labour in minutes; CS due to failure to progress.
Notes

No other oral intake; no food.

No epidurals.

Risk of bias
BiasAuthors' judgementSupport for judgement
Random sequence generation (selection bias)Unclear riskWomen were randomised but the study does not specify method of randomisation.
Allocation concealment (selection bias)Unclear riskPossible selection bias. Unclear details.
Incomplete outcome data (attrition bias)
All outcomes
Low riskNo attrition reported.
Selective reporting (reporting bias)Low riskFairly transparent results.
Other biasUnclear riskNo details about duration of study.
Blinding of participants and personnel (performance bias)
All outcomes
High riskNot mentioned.
Blinding of outcome assessment (detection bias)
All outcomes
Low riskDetailed reporting of outcome assessment.

Coco 2010

MethodsProspective randomised trial.
Participants

Nulliparous women in spontaneous active labour with a singleton, vertex presentation ≥ 37 weeks' gestation were included. Women were eligible for inclusion if dilatation was between 2 and 5 cm, with or without ruptured membranes.

220 women were recruited.

116 women excluded due to preterm delivery, pre-eclampsia or scheduled CS.

11 women excluded as fluids were delayed.

4 women did not have consent forms.

9 women delivered elsewhere so were lost to follow-up.

80 women fulfilled criteria for inclusion and were analysed.

Interventions

37 women received 250 mL of lactated Ringer’s solution IV per hour (IV fluid group) and 43 women received "usual care".

Usual care consisted of lactated Ringer’s solution IV for medical indications at the discretion of the provider. The women in this group received a mean volume of 1627 mL of fluid.

Both groups were allowed unrestricted oral intake of fluids.

OutcomesDuration of labour; first, second stage and total duration.
NotesUnrestricted oral fluids (water, juice, carbonated drinks) amounts recorded in both groups.
Risk of bias
BiasAuthors' judgementSupport for judgement
Random sequence generation (selection bias)Low riskRandom number chart.
Allocation concealment (selection bias)Low riskConsecutively numbered opaque sealed envelopes.
Incomplete outcome data (attrition bias)
All outcomes
High risk

Large attrition due to recruitment taking place antenatally rather than at the onset of labour.

Clear explanatory notes when attrition occurred.

220 women were recruited.

116 women excluded due to preterm delivery, pre-eclampsia or scheduled CS.

11 women excluded as fluids were delayed.

4 women did not have consent forms.

9 women delivered elsewhere so were lost to follow-up.

80 women fulfilled criteria for inclusion and were analysed.

Selective reporting (reporting bias)Low riskProspective data capture.
Other biasUnclear risk

No restriction on oral fluid intake may have influenced results; inherent bias of women drinking as much as possible, although similar mean oral intake in both groups.

Women recruited from 4 hospitals including 3 private practices.

Blinding of participants and personnel (performance bias)
All outcomes
High risk

Unclear as to whether measures were taken to blind personnel.

Participants: potential bias in that they were informed about increased fluids in labour and allowed to drink.

Potential bias as participants recruited antenatally and could have influenced the amount of fluids ingested orally.

Blinding of outcome assessment (detection bias)
All outcomes
Low riskProspective analysis by nursing staff.

Direkvand-Moghadam 2012

MethodsProspective randomised controlled trial. 4 arms with individual randomisation.
Participants

120 women in labour at a hospital in Ilam, Iran in 2010.

Inclusion criteria: nulliparity, aged between 18-35 years, singleton pregnancy, spontaneous active labour (defined as cervical dilatation of 4 to 5 cm), gestational age 38-40 weeks, normal fetal heart tracings, intact membranes and vertex presentation. Labour analgesia was not used.

Exclusion criteria: elective labour induction, emergency CS, known cephalopelvic disproportion, diagnosed pre-eclampsia, chorioamnionitis, pyelonephritis, maternal cardiac or renal disease, IUGR, cervix dilated > 5 cm.

Interventions

4 groups: 30 women in each group

  1. Control. Free oral fluids (no IV fluids).

  2. Free oral fluids + IV Ringer lactate solution at infusion rate of 60 mL/hour.

  3. Free oral fluids + IV Ringer lactate solution at infusion rate of 120 mL/hour.

  4. Free oral fluids + IV Ringer lactate solution at infusion rate of 60 mL/hour.

In all groups partograms were used to monitor progress in labour. Amniotomy was performed by a midwife when cervical dilatation reached 5 cm if membranes had not ruptured spontaneously. At one hour after amniotomy, if uterine contractions were less than 3 in ten minutes, or dilation was less than 1.2 cm per hour, oxytocin was used for labour augmentation.

OutcomesDuration of active phase of first stage of labour, duration of 2nd and 3rd stages of labour, need for oxytocin augmentation, mode of delivery, Apgar scores at 1 and 5 minutes.
NotesIn the data and analyses in this review for comparison 4 (IV fluids plus oral intake vs oral intake alone) we have combined results for the three groups receiving IV fluids to allow a single pair-wise comparison between women receiving IV fluids plus oral fluids vs oral fluids alone. This study is also included in comparison 5 where different hourly rates of infusion are compared.
Risk of bias
BiasAuthors' judgementSupport for judgement
Random sequence generation (selection bias)Low riskRandom number tables.
Allocation concealment (selection bias)Low riskOpaque, sealed, consecutively numbered envelopes.
Incomplete outcome data (attrition bias)
All outcomes
Low risk120 women were randomised and all seemed to be accounted for in the analysis. There was no mention of missing data for any outcome.
Selective reporting (reporting bias)Unclear riskAssessment from published study report.
Other biasUnclear riskIn the methods section it was stated that the 4 groups were “matched” for inclusion criteria. It was not clear what this meant.
Blinding of participants and personnel (performance bias)
All outcomes
High riskBlinding women or staff to this intervention was not mentioned. Lack of blinding may have affected staff behaviour and outcome assessment.
Blinding of outcome assessment (detection bias)
All outcomes
High risk It was not mentioned whether any outcome data were collected by blind outcome assessors. Lack of blinding may have affected staff behaviour and outcome assessment.

Eslamian 2006

MethodsProspective double-blind randomised trial.
Participants

300 nulliparous women enrolled; all women went in to spontaneous labour at term; singleton pregnancies; cephalic presentation.

153 randomised to 125 mL/hour; 147 women randomised to 250 mL/hour.

Interventions2 different volumes of Ringer's lactate solution (125 mL/hour vs 250 mL/hour).
OutcomesDuration of labour in minutes; CS due to failure to progress; assisted delivery.
NotesNil by mouth; no epidurals.
Risk of bias
BiasAuthors' judgementSupport for judgement
Random sequence generation (selection bias)Low riskRandom computer-generated numbers.
Allocation concealment (selection bias)Low riskConsecutively numbered opaque sealed envelopes.
Incomplete outcome data (attrition bias)
All outcomes
Low riskDetailed outcome data available for all 300 recruited women.
Selective reporting (reporting bias)Low riskNo evidence of selective reporting.
Other biasUnclear riskAuthors acknowledge the following: no measurements of inherent maternal dehydration; no measurements of skin turgor, osmolality.
Blinding of participants and personnel (performance bias)
All outcomes
Low riskDouble-blinded study with clear evidence of double-blinding measures.
Blinding of outcome assessment (detection bias)
All outcomes
Low riskNone apparent.

Garite 2000

MethodsProspective randomised trial.
Participants195 nulliparous women in term spontaneous labour with a singleton pregnancy, cephalic presentation.
Interventions

125 mL/hour vs 250 mL/hour of Ringer's lactate solution.

94 women received 125 mL/hour while 101 women received the higher volume of 250 mL/hour.

Outcomes

Maternal: duration of labour in minutes

Maternal/fetal: need for CS or assisted delivery/Apgar < 7; admission to SCBU.

NotesNo food; no oral fluid intake; sips of water only; ice chips allowed.
Risk of bias
BiasAuthors' judgementSupport for judgement
Random sequence generation (selection bias)Low riskRandom computer-generated sequence.
Allocation concealment (selection bias)Low riskConsecutively numbered opaque sealed envelopes.
Incomplete outcome data (attrition bias)
All outcomes
Low riskNone of the women randomised needed to be excluded.
Selective reporting (reporting bias)Low riskNone apparent.
Other biasUnclear riskNo measurement of inherent maternal dehydration; no assessment of serum/urine osmolality.
Blinding of participants and personnel (performance bias)
All outcomes
High riskNo masking of interventions.
Blinding of outcome assessment (detection bias)
All outcomes
Low riskNone apparent.

Kavitha 2012

MethodsRandomised controlled trial.
Participants293 nulliparous women with term spontaneous labours between 3- 6 cm dilatation, singleton pregnancy, cephalic presentation.
Interventions

99 women received oral hydration.

98 women were randomised to receive 125 mL/hour of Ringer's lactate and oral fluids.

96 women were randomised to receiving 250 mL/hour of Ringer's lactate and oral fluids.

Outcomes

Maternal: duration of labour, mode of delivery, CS delivery for failure to progress, vomiting.

Fetal: admission to NICU.

NotesOral fluids was allowed in all study groups (no quantification of volumes required).
Risk of bias
BiasAuthors' judgementSupport for judgement
Random sequence generation (selection bias)Low riskComputerised block randomisation.
Allocation concealment (selection bias)Low riskSequential opaque envelopes.
Incomplete outcome data (attrition bias)
All outcomes
Low riskComplete outcomes for all participants; no attrition.
Selective reporting (reporting bias)Low riskNone apparent.
Other biasHigh risk

Women in control group (oral fluids) were allowed either plain fluids or coconut water (no clear discussion about possible bias with coconut water).

In IV fluid groups, maximum quantity of IV fluids was restricted to 3 litres "to prevent fluid overload".

Blinding of participants and personnel (performance bias)
All outcomes
High riskNo masking of interventions.
Blinding of outcome assessment (detection bias)
All outcomes
Low riskNone apparent.

Maderia 2007

MethodsProspective randomised trial.
Participants

59 nulliparous women in term spontaneous labours with a singleton pregnancy, cephalic presentation.

30 women received 125 mL/hour; 29 women received 250 mL/hour.

Interventions125 mL/hour vs 250 mL/hour of unspecified IV fluid.
OutcomesDuration of labour in minutes; CS due to failure to progress.
NotesNil by mouth; only ice-chips.
Risk of bias
BiasAuthors' judgementSupport for judgement
Random sequence generation (selection bias)Unclear riskNo information (abstract only).
Allocation concealment (selection bias)High riskNo information (abstract only); does not specify what type of IV fluid administered.
Incomplete outcome data (attrition bias)
All outcomes
Unclear riskNo information (abstract only).
Selective reporting (reporting bias)Unclear riskNo information (abstract only).
Other biasUnclear riskNo information (abstract only).
Blinding of participants and personnel (performance bias)
All outcomes
Unclear riskNo information (abstract only).
Blinding of outcome assessment (detection bias)
All outcomes
Unclear riskNo information (abstract only).

Shrivastava 2009

MethodsProspective double-blinded randomised controlled trial.
Participants

300 nulliparous women in term spontaneous labour with a singleton pregnancy, cephalic presentation enrolled.

5 women were withdrawn by their physician.

3 women did not meet inclusion criteria.

3 women had incomplete data collection.

11 women were not included in data analysis.

2 women were excluded (1 with diabetes mellitus 1 who developed pre-eclampsia).

289 women completed the study.

Interventions

3 different groups:
97 women randomised to receive normal saline 125 mL/hour.

94 women randomised to receive 5% dextrose 125 mL/hour.

98 women randomised to receive 10% dextrose 125 mL/hour.

Outcomes

Maternal: duration of first, second stages of labour and total duration of labour, CS.

Fetal/neonatal: admission to neonatal unit, Apgar scores < 7 at 5 minutes, hyperbilirubinaemia requiring therapy, cord pH < 7.20, arterial cord glucose, hypoglycaemia at 1 and 2 hours.

NotesNil by mouth; ice chips only.
Risk of bias
BiasAuthors' judgementSupport for judgement
Random sequence generation (selection bias)Low riskComputer-generated randomisation.
Allocation concealment (selection bias)Low riskConsecutively numbered opaque sealed envelopes by pharmacy staff.
Incomplete outcome data (attrition bias)
All outcomes
Low risk

Clear documentation of excluded women when incomplete data collection and clear documentation of reasons for attrition:

300 nulliparous women in term spontaneous labours with a singleton pregnancy, cephalic presentation enrolled.

5 women were withdrawn by their physician.

3 women did not meet inclusion criteria (1 with diabetes mellitus, 1 who developed pre-eclampsia and 1 woman < 18 years).

3 women had incomplete data collection.

11 women were not included in data analysis.

289 women completed the study.

Selective reporting (reporting bias)Low riskClear flow-diagrams and different tables for maternal and neonatal outcomes.
Other biasUnclear riskInsufficiently powered for neonatal outcomes.
Blinding of participants and personnel (performance bias)
All outcomes
Low riskDouble-blinded study; blinding by pharmacy personnel; each group assigned A, B, C and changed after every 80 women to minimise observer bias; IV bags were covered with non-transparent adhesive tapes to ensure double-blinding.
Blinding of outcome assessment (detection bias)
All outcomes
Low riskAdequate measures as above to ensure double-blinding.

Stratton 1995

  1. a

    CS: caesarean section
    IUGR: intrauterine growth restriction
    IV: intravenous
    NICU: neonatal intensive care unit
    SCBU: special care baby unit
    vs: versus

MethodsProspective randomised trial.
Participants

100 primigravid women in spontaneous labour.

7 women randomised but no blood taken so excluded from analysis.

4 other women declined consent.

2 other women excluded as no consent obtained by medical staff.

Interventions5% dextrose vs normal saline for oxytocin augmentation.
Outcomes

Maternal : delivery outcomes, mean duration of labour, CS, maternal hyponatraemia, fluid overload.

Fetal: neonatal hyponatraemia. admission to NICU.

NotesSubgroup of women with epidurals.
Risk of bias
BiasAuthors' judgementSupport for judgement
Random sequence generation (selection bias)Low riskRandom allocation.
Allocation concealment (selection bias)Low riskSealed envelopes.
Incomplete outcome data (attrition bias)
All outcomes
Low riskClear explanations for attrition due to omission of obtaining blood samples; failure to obtain consent.
Selective reporting (reporting bias)Low riskDetailed explanations for all outcomes.
Other biasHigh riskA subgroup of women were given additional fluids as part of their epidurals.
Blinding of participants and personnel (performance bias)
All outcomes
Unclear riskNot clearly apparent that study was double-blind.
Blinding of outcome assessment (detection bias)
All outcomes
Unclear riskOutcomes not blinded.

Characteristics of excluded studies [ordered by study ID]

StudyReason for exclusion
  1. a

    multip: (multipara) a woman who has delivered two or more babies
    nullip: (nulligravida) a woman who has never been pregnant
    primip: (primigravida) a women who has given birth once

Boylan 1980

Open and double-blind study.

Participants: unclear whether nullips or multips; also in a subgroup, labour was induced.

Interventions: intravenous bolus of glucose versus Hartmann's.

Outcome: fetal breathing; no maternal outcomes.

Caspi 1979

Method: appears to be a case-controlled study.

There is no evidence that women were randomly assigned to the 2 groups.

Participants: 22 primips.

Intervention: sodium bicarbonate infusion.

Cerri 2000

Participants: 81 women but no distinction between nullips and multips.

Intervention: 43 women received 5% glucose and 38 women did not receive any fluids.

Cheek 1996

Prospective randomised controlled trial.

Participants: 34 labouring women (no clear distinction in outcomes between nullips and multips).

Interventions: extradural normal saline and glucose.

Fisher 1997

Abstract only, so limited information.

Participants: multips and nullips.

Haesslein 1975

Participants: all low-risk labouring women (nullips and multips).

Interventions: 5% dextrose in water versus 5% dextrose in saline.

Outcome: maternal hypertension.

Higgins 1996

Randomised controlled trial.

Interventions; oxytocin in Hartmann's solution compared with the standard 5% dextrose regimen for induction or augmentation in labour.

Outcomes: maternal serum sodium.

Good study with clear randomisation method; reason for exclusion was non-spontaneous labour.

Hofmann 2001

Participants: labouring women in their first or second pregnancy (no distinction between nullips and multips).

Interventions: glucose was compared with a glucose substitute treatment (Xylit) and an electrolyte treatment (Sterofundin).

Jamal 2007

Randomised controlled trial.

Participants: 178 women but all were multiparous (at least para 1).

Intervention: 120 mL/hour of 5% dextrose was compared with the same volume of Ringer's lactate.

Outcomes: primary outcome was fetal acid-base status.

Kenepp 1985

Randomised trial.

Participants: 31 term labourers; unclear whether nullips or multips or both.

Intervention: different concentrations of dextrose solutions.

Outcomes; ketoacidosis.

Limited information about duration of labour and other outcomes as published as abstract only.

Loong 1987

Prospective randomised trial.

Participants: 48 women (nullips and multips).

Interventions: 5% dextrose solution or Hartmann's solution.

Outcomes: maternal and cord blood glucose.

Reason for exclusion: although there was a distinction between nullips and multips in the demographics, there was no distinction in the outcomes in terms of parity.

Menigaux 1993

Randomised controlled trial.

Participants: 20 labouring women having epidurals (study does not specify whether nullips or multips).

Interventions: 50% dextrose versus Ringer's lactate in women who were given a basal infusion of 100 mL/hour Ringer's lactate before an epidural.

Outcome: maternal and neonatal hypoglycaemia.

Abstract only.

Navarette,1982

Randomised controlled trial.

Participants: insufficient information on parity.

Outcome: intrapartum metabolic control.

Nordstrom 1995All participants were on average para 1 therefore excluded.
Omigbodun 1989

Participants: all women who required oxytocin for induction of labour or augmentation (so non-spontaneous labours). Furthermore, no distinction regarding parity.

Intervention: normal saline or 5% glucose with oxytocin.

Outcomes: maternal postpartum blood pressure.

Omigbodun 1991

Participants: all women who required oxytocin for induction of labour or augmentation (so non-spontaneous labours). Furthermore, no distinction regarding parity.

Intervention: normal saline or 5% glucose with oxytocin.

Outcomes: maternal postpartum sodium levels; cord sodium levels.

Omigbodun 1993Interventions: all women received oxytocin.
Oral 2003

Participants: nullips and multips included; control group comprised entirely of multiparous women.

Interventions: oxytocin for augmentation.

Outcomes: neonatal bilirubin levels.

Rooth 1967

Limited information available, published as abstract only.

Participants: 60 labouring women; unclear whether nulliparous or not; no details of randomisation.

Interventions: sodium bicarbonate given to half the participants.

Rosenberg 2006Participants: all women in this study were insulin requiring gestational diabetics therefore excluded.
Simpson 2005Participants: 42 women were randomised to either a 500 mL or 1000 mL intravenous fluid bolus over 20 minutes. All women were either being induced or having this bolus as a preload for epidurals.
51 women were randomised to 1 of 6 position sequences including supine with the head elevated 30°, left lateral and right lateral for 15 minutes each in succession.
Singhi 1982

Study published as part of Letter-to-the Editor.

Participants: no mention of parity; so difficult to interpret results.

Thaler 2007

Participants: 85 women; unclear whether nullips or multips.

Interventions: 10% glucose versus Ringer's lactate.

Abstract only; limited information.

Watson 2012

Randomised controlled trial.

Participants: nulliparous or multiparous women requesting epidurals and who intended to breastfeed.

Interventions: different volumes of epidural preload.

Outcome measures: effect on weight loss on the newborn.

Wells-Brooks 2001

Methods: quasi-experimental research design.

Participants: labouring women receiving combined spinal epidural anaesthesia.

Interventions: different volumes of intravenous fluids in women receiving combined spinal epidural anaesthesia.

Outcome measures: frequency of uterine contractions.

Wright 2000

Prospective randomised double-blind study.

Participants: 32 insulin requiring diabetic women randomised to 2 different dextrose infusions.

Characteristics of studies awaiting assessment [ordered by study ID]

Amir 2004

MethodsThis study was identified by the search, but we have not yet been able to locate a copy of the paper.
Participants 
Interventions 
Outcomes 
Notes 

Rad 2012

  1. a

    IV: intravenous

MethodsDescribed as a "randomized clinical trial".
Participants97 primiparous women.
Interventions

Group 1. IV normal saline 120 mL/minute.

Group 2. IV dextrose 5% in normal saline 120 mL/minute.

OutcomesCervical dilatation, duration of 2nd stage of labour, need for oxytocin, caesarean section, Apgar score at 1 and 5 minutes, neonatal hypoxia.
NotesThis study was reported in a paper published in Iranian. We are awaiting full translation in order to assess risk of bias and to carry out data extraction. (Brief abstract in English.)

Characteristics of ongoing studies [ordered by study ID]

Salim 2011

Trial name or titleIntrapartum Hydration
MethodsRandomised controlled trial.
ParticipantsNulliparous women in spontaneous labour; singleton pregnancy, gestational age 37-41 weeks.
InterventionsIntravenous fluids: 0.9 % saline with 5% glucose solution at rate of 125 mL/hour versus 250 mL/hour Ringer's lactate.
Outcomes
  • Duration of labour

  • Mode of delivery

Starting dateNovember 2010.
Contact information

Raed Salim

salim ra @clalit.org.il

NotesStatus of study: still recruiting.

Ancillary