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Early amniotomy and early oxytocin for prevention of, or therapy for, delay in first stage spontaneous labour compared with routine care

  1. Shuqin Wei1,
  2. Bi Lan Wo1,
  3. Hui-Ping Qi2,
  4. Hairong Xu1,
  5. Zhong-Cheng Luo1,
  6. Chantal Roy3,
  7. William D Fraser1,*

Editorial Group: Cochrane Pregnancy and Childbirth Group

Published Online: 7 AUG 2013

Assessed as up-to-date: 8 JUL 2013

DOI: 10.1002/14651858.CD006794.pub4


How to Cite

Wei S, Wo BL, Qi HP, Xu H, Luo ZC, Roy C, Fraser WD. Early amniotomy and early oxytocin for prevention of, or therapy for, delay in first stage spontaneous labour compared with routine care. Cochrane Database of Systematic Reviews 2013, Issue 8. Art. No.: CD006794. DOI: 10.1002/14651858.CD006794.pub4.

Author Information

  1. 1

    Université de Montréal, Département d'Obstétrique-Gynécologie, Montréal, Province of Quebec, Canada

  2. 2

    First Affiliated Hospital, Harbin Medical University, Department of Obstetrics and Gynecology, Harbin, China

  3. 3

    CHU Ste-Justine, Unité de recherche clinique appliquée, Montreal, Quebec, Canada

*William D Fraser, Département d'Obstétrique-Gynécologie, Université de Montréal, Hôpital Sainte-Justine, Bureau 4986, 3175 Chemin de la côte Sainte-Catherine, Montréal, Province of Quebec, H3T 1C5, Canada. william.fraser@umontreal.ca.

Publication History

  1. Publication Status: New search for studies and content updated (no change to conclusions)
  2. Published Online: 7 AUG 2013

SEARCH

 

Background

  1. Top of page
  2. Background
  3. Objectives
  4. Methods
  5. Results
  6. Discussion
  7. Authors' conclusions
  8. Acknowledgements
  9. Data and analyses
  10. Appendices
  11. What's new
  12. History
  13. Contributions of authors
  14. Declarations of interest
  15. Sources of support
  16. Index terms

Caesarean section rates are over 20% in many developed countries (Betran 2007) and have increased nearly four-fold relative to the 5% rate observed in the early 1970s (NCCWCH 2004). The main diagnosis contributing to this increase is dystocia or prolonged labour (Anderson 1989; Liu 2004). Factors such as increasing maternal age appear to have contributed to the increase in the incidence of dystocia (Treacy 2006).

The 'active management' of labour is a clinical protocol that was designed to facilitate the organization of obstetric care in a busy labour ward. The active management of labour has been proposed as an alternative approach to the problem of dystocia, as well as a strategy to reduce the high rate of caesarean sections (O'Driscoll 1984). Active management includes: selective admission to the labour ward; selective use of electronic fetal monitoring; early intervention with amniotomy and oxytocin for delay in labour progress; routine use of a simplified 1 cm/hour partogram to guide clinical decision making; and continuous professional support. Classically, the protocol has included restricted use of epidural analgesia. To date, there is no consensus with respect to the timing of amniotomy and oxytocin administration in the presence of a delay in labour.

 

Description of the condition

Dystocia is a term used for delay of labour progress and usually refers to abnormally slow cervical dilatation. O'Driscoll proposed a partogram that includes, as a diagnostic criterion, a 1 cm/hour line originating at admission (O'Driscoll 1984). In contrast, Philpott suggested that the intervention threshold for dystocia should be based on an action line which is parallel to that proposed by O'Driscoll, but four hours to the right (Philpott 1982). Peisner noted that a high proportion of nulliparous women enter active phase dilatation only after 4 cm (Peisner 1986). This would argue against early intervention prior to 4 cm dilatation. The World Health Organization has proposed a modified partogram that recommends that active phase be diagnosed only at 4 cm or more (WHO 2000).

 

Description of the intervention

Active management is a protocol that includes strict criteria for the diagnosis of labour, early amniotomy, prompt oxytocin with high-dose oxytocin in the event of inefficient uterine action, and continuous professional support during labour. A policy of combining early amniotomy with early oxytocin administration, which are applied sequentially in the active management of labour, are the key medical components of this approach to care. Several trials which have been labelled by the author as a trial of active management have only contrasted the used of early oxytocin and early amniotomy relative to routine care. Other studies of early amniotomy and early oxytocin, not labelled as active management trials, have been conducted. This review assessed the effects of early amniotomy and early oxytocin versus a more conservative form of management in the context of care.

 

How the intervention might work

Active management is based on the hypothesis that the most frequent cause of dystocia is inadequate uterine action: true cephalopelvic disproportion is assumed to be an infrequent cause of dystocia (O'Driscoll 1970). Amniotomy and oxytocin are performed with the purpose of increasing the frequency and intensity of contractions. Both the administration of oxytocin and amniotomy have been demonstrated to increase the frequency and intensity of uterine contractions (Blanks 2003). As dystocia is primarily a problem of women who are in their first labour, active management focuses on nulliparous women. Clearly, the active management protocol proposes a low threshold for intervention for delay in labour progress. Early intervention is not without its risks. Uterine hyperstimulation and fetal heart rate abnormalities may result from oxytocin and amniotomy. The frequency of such complications needs to be better quantified.

 

Why it is important to do this review

Early amniotomy and oxytocin influence the overall organization of intrapartum obstetric care; therefore, this review is relevant to clinicians, consumers, and policy makers. For clinicians and consumers, the key issues are the effect of early augmentation in labour on indicators of morbidity and satisfaction with care. For policy makers, the key issues are the impact on the organization of care, including the appropriate settings and technical support required for routine obstetric care and their costs.

 

Objectives

  1. Top of page
  2. Background
  3. Objectives
  4. Methods
  5. Results
  6. Discussion
  7. Authors' conclusions
  8. Acknowledgements
  9. Data and analyses
  10. Appendices
  11. What's new
  12. History
  13. Contributions of authors
  14. Declarations of interest
  15. Sources of support
  16. Index terms

  1. To estimate the effects, among unselected women, of a policy of early augmentation with amniotomy and oxytocin (prevention) on the caesarean birth rate and on indicators of maternal and neonatal morbidity.
  2. To evaluate the effects, among women with established delay in labour progress, of early augmentation with amniotomy plus oxytocin (therapy) on the caesarean birth rate and on indicators of maternal and neonatal morbidity.

 

Methods

  1. Top of page
  2. Background
  3. Objectives
  4. Methods
  5. Results
  6. Discussion
  7. Authors' conclusions
  8. Acknowledgements
  9. Data and analyses
  10. Appendices
  11. What's new
  12. History
  13. Contributions of authors
  14. Declarations of interest
  15. Sources of support
  16. Index terms
 

Criteria for considering studies for this review

 

Types of studies

Randomized or quasi-randomized studies.

 

Types of participants

Pregnant women in spontaneous labour.

Types of participants are divided into two separate groups:

  1. unselected pregnant women in spontaneous labour;
  2. pregnant women in spontaneous labour where there is delay in the first stage.

 

Types of interventions

Early augmentation with amniotomy and oxytocin versus a more conservative form of management in the context of care. Trials where patients in both groups underwent amniotomy were excluded from this review.

 

Types of outcome measures

 

Primary outcomes

Caesarean section rate.

 

Secondary outcomes

 
Maternal

Related to delivery method and labour duration

  1. Spontaneous vaginal delivery
  2. Instrumental vaginal delivery (forceps or vacuum, or both)
  3. Length of first stage of labour
  4. Duration of labour (duration in hours from admission in labour)
  5. Satisfied with labour experience

 
Related to pain

  1. Use of epidural analgesia

 
Potential adverse effects

  1. Hyperstimulation of labour
  2. Postpartum haemorrhage (greater than 500 mL)
  3. Maternal blood transfusion
  4. Postpartum fever or infection

 
Fetal/infant

  1. Apgar score less than seven at five minutes
  2. Acidosis as defined abnormal arterial cord pH (pH less than 7.10 or 7.20)
  3. Suboptimal or abnormal fetal heart tracing
  4. Fetal distress
  5. Admission to special care nursery
  6. Seizure/neurological abnormalities
  7. Jaundice or hyperbilirubinaemia

Some outcomes proposed in the protocol were not included in the review because there were no data available in the included trials. Future updates of this review will include these outcomes if data become available. These outcomes are:

  1. women's use of non-epidural analgesia;
  2. level of pain;
  3. perineal trauma;
  4. antepartum haemorrhage;
  5. serious maternal morbidity or death;
  6. maternal health service utilization (cost);
  7. infant health service utilization (cost).

Future clinical trials are needed for these effects.

 

Search methods for identification of studies

 

Electronic searches

We searched the Cochrane Pregnancy and Childbirth Group’s Trials Register by contacting the Trials Search Co-ordinator (31 May 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.  

In addition, we searched MEDLINE (1966 to 4 July 2013), Embase (1980 to 4 July 2013), CINAHL (1982 to 4 July 2013) and MIDIRS (1985 to 4 July 2013) (Appendix 1).

 

Searching other resources

We obtained data from any unpublished trials through direct communication with the authors.

We did not apply any language restrictions.

 

Data collection and analysis

For the methods used when assessing the trials identified in the previous version of this review, see Appendix 2.

For this update we used the following methods when assessing the reports identified by the updated search.

 

Selection of studies

Three review authors (SQ Wei, BL Wo and HP Qi) independently assessed for inclusion all the potential studies identified as a result of the search strategy. We excluded studies where women in both treatment groups underwent amniotomy. We resolved any disagreement through discussion or consulted a third author (WD Fraser).

 

Data extraction and management

We designed a form to extract data. For eligible studies, at least two review authors (SQW, BL Wo or HPQ) extracted the data independently. We resolved discrepancies through discussion or consulted a third author (WD Fraser). We entered data into Review Manager software (RevMan 2011) and checked them for accuracy. When information regarding any of the above was unclear, we attempted to contact authors of the original reports to provide further details.

 

Assessment of risk of bias in included studies

Three review authors (SQ Wei, HP Qi and HR Xu) 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 or by involving a fourth author (WD Fraser).

 

(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 described for each included study the method used to conceal allocation to interventions prior to assignment and assessed 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 randomization; 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 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 that studies were 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 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 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 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 stated whether attrition and exclusions were reported and the numbers included in the analysis at each stage (compared with the total randomized 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 can be supplied by the trial authors, we re-included missing data in the analyses which we have undertaken.

We assessed methods as:

  • low risk of bias (e.g. where there was no missing data or low levels of missing data,and where reasons for missing data were balanced across groups);
  • high risk of bias (e.g. where there were high levels of missing data or where attrition was not balanced across groups);
  • unclear risk of bias.(e.g. where there was insufficient reporting of attrition or exclusions to permit a judgement to be made).

(For outcomes measured in labour, we would expect low levels of missing data to be no more than 10%.)

 

(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 was 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 were reported incompletely and so could not be used; study failed 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. For example, where there was a potential source of bias related to the specific study design, where the protocol changed part-way through, where there was extreme baseline imbalance, or where the study had been claimed to be fraudulent.

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 risk of bias for important outcomes both within and across studies. 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 findings. We set out assessments of bias for included studies in the 'Risk of bias' tables. We explored the impact of the level of bias through undertaking sensitivity analyses. 

 

Measures of treatment effect

 

Dichotomous data

For dichotomous data, we 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 standardized mean difference to combine trials that measured the same outcome, but used different methods.  

 

Unit of analysis issues

 

Cluster-randomized trials

We did not identify any cluster-randomized trials on this topic.

 

Other unit of analysis issues

We excluded cross-over trials.

 

Dealing with missing data

For included studies, we noted levels of attrition.

We analyzed 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, on an intention-to-treat basis.

 

Assessment of heterogeneity

We applied tests of heterogeneity between trials, if appropriate, using T², I² and Chi² statistics. We regarded heterogeneity as substantial if the I² was greater than 30% and either T² was greater than zero, or there was a low P value (less than 0.10) in the Chi² test for heterogeneity. If this was the case, then a random-effects meta-analysis was used as an overall summary.

 

Assessment of reporting biases

Where we suspected reporting bias or where missing data were thought to introduce serious bias, this has been reported.

 

Data synthesis

We carried out statistical analysis using the Review Manager software (RevMan 2011). We used fixed-effect inverse variance meta-analysis for combining data where trials were examining 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 between trials, we used random-effects meta-analysis.

If substantial heterogeneity was identified in a fixed effect meta-analysis, the analysis was repeated using a random-effects method.

If we used random-effects analyses, the results were presented as the average treatment effect with 95% confidence intervals, and the estimates of  T² and I².

 

Subgroup analysis and investigation of heterogeneity

We conducted the following subgroup analyses.

  1. 'Prevention Trials', which were defined as trials that included unselected women in early spontaneous labour who were allocated to either early amniotomy and oxytocin in the case of delay in progress, or to usual care.
  2. 'Therapy Trials', which were defined as trials that only included women with an established delay in labour progress. In these trials, women had been allocated to either early amniotomy and oxytocin, or to routine care.

We conducted subgroup analyses on all outcomes.

We planned to assess differences between subgroups by interaction tests available in RevMan 2011.

 

Sensitivity analysis

We carried out a sensitivity analysis to explore the effects of a policy of early amniotomy and oxytocin alone, without the full package of co-interventions that are usually considered as constituting active management: continuous professional care, selective admission at the labour ward. Four such studies of active management (Frigoletto 1995; Rogers 1997; Snehlata 2011; Tabowei 2003) were excluded in the sensitivity analysis in order to assess the combined effect of early amniotomy and oxytocin on the primary outcome.

 

Results

  1. Top of page
  2. Background
  3. Objectives
  4. Methods
  5. Results
  6. Discussion
  7. Authors' conclusions
  8. Acknowledgements
  9. Data and analyses
  10. Appendices
  11. What's new
  12. History
  13. Contributions of authors
  14. Declarations of interest
  15. Sources of support
  16. Index terms
 

Description of studies

 

Results of the search

We identified 24 studies. Ten were excluded.

 

Included studies

Fourteen trials including 8033 women in labour were analyzed. The characteristics of the women at the time of admission to the studies are shown in  Table 1. Twelve randomized control trials (Blanch 1998; Bréart 1992; Cammu 1996; Cluett 2004; Frigoletto 1995; Lopez-Zeno 1992; Nachum 2010; Rogers 1997; Sadler 2000; Snehlata 2011; Somprasit 2005; Tabowei 2003) and two quasi-randomized trials (Cohen 1987; Serman 1995) were included in this review, see Characteristics of included studies. In one study (Frigoletto 1995), randomization was performed at the beginning of the third trimester and approximately one-third of the women were excluded from the analysis after randomization as they became ineligible for the intervention. Only caesarean section (CS) was reported by intention-to-treat. This study was only included for the CS outcome. Eleven trials the enrolled women who were in normal spontaneous labour at randomization, allocating them either to early amniotomy and oxytocin if slow progress in labour ensued or to expectant management. These studies were termed 'prevention studies' (Bréart 1992; Cammu 1996; Cohen 1987; Frigoletto 1995; Lopez-Zeno 1992; Rogers 1997; Sadler 2000; Serman 1995; Snehlata 2011; Somprasit 2005; Tabowei 2003). Three trials (Blanch 1998; Cluett 2004; Nachum 2010) which included only women with an established abnormality in the progress of labour were grouped as 'therapy' trials. Twelve trials were conducted in nulliparous women (Bréart 1992; Cammu 1996; Cluett 2004; Cohen 1987; Frigoletto 1995; Lopez-Zeno 1992; Rogers 1997; Sadler 2000; Serman 1995; Snehlata 2011; Somprasit 2005; Tabowei 2003). Two trials were conducted in a mixed population of nulliparous and multiparous women (Blanch 1998; Nachum 2010). No studies were conducted solely in multiparous women. There were four trials of active management of labour (Frigoletto 1995; Rogers 1997; Snehlata 2011; Tabowei 2003) which, in the experimental intervention, included strict criteria for the diagnosis of labour, early amniotomy, prompt oxytocin with high-dose oxytocin in the event of inefficient uterine action and continuous professional support.

In all studies, the more interventionist policy consisted of early amniotomy if membranes were intact and early oxytocin infusion. Oxytocin was used in women in the control group if a more marked delay in labour progress ensued. The severity of delay which justified oxytocin augmentation in the control group varied from usual care to an eight-hour period of expectant management following randomization. Care of the amniotic membranes for women in control groups also varied across trials.There was either an attempt to avoid amniotomy in control group women (Bréart 1992; Cammu 1996; Lopez-Zeno 1992; Nachum 2010; Rogers 1997; Sadler 2000; Serman 1995) or membranes were managed according to usual care 'no attempt to modify care from what is usually given on the service' (Cluett 2004; Cohen 1987; Frigoletto 1995; Snehlata 2011; Somprasit 2005; Tabowei 2003). Studies varied in the degree of contrast achieved between groups with respect to the proportion undergoing the interventions (see Characteristics of included studies for details). In some trials, the proportion of women receiving oxytocin was similar in the two groups (Bréart 1992; Lopez-Zeno 1992; Rogers 1997; Serman 1995). However, in these studies, the groups contrasted in respect of the time between randomization and the initiation of oxytocin.

 

Excluded studies

The characteristics of the excluded studies are outlined in the Characteristics of excluded studies table. In the study by Rouse (Rouse 1994), study groups differed only with respect to the use of amniotomy. In Yasmin 2002, the intervention was 'routine amniotomy' and not 'early amniotomy'. The trial by Cardozo 1990 was excluded as the groups differed only in the use of oxytocin. In Hogston 1993, the method of allocation depended on the labour ward policies of the woman's treating physician. One study (Ruiz Ortiz 1991), was a non-randomized trial. There was no control group in two other studies (Cummiskey 1989; Xenakis 1995). Two trials were for induction labour, not augmentation (Gagnon-Gervais 2011; Selo-Ojeme 2009). Finally, in one study (Verkuyl 1986), there was no information on the inclusion or exclusion characteristics of the women.

 

Risk of bias in included studies

See Figure 1 and Figure 2, for summaries of all 'Risk of bias' assessments.

 FigureFigure 1. 'Risk of bias' graph: review authors' judgements about each risk of bias item presented as percentages across all included studies.
 FigureFigure 2. 'Risk of bias' summary: review authors' judgements about each risk of bias item for each included study.

We independently considered 14 trials for randomization method and attrition bias. Amniotomy is virtually impossible to mask, and oxytocin was not blinded in the trials. In one trial (Snehlata 2011), there is only abstract information available, we could not evaluate the risk of bias for allocation, outcome data, reporting and other potential sources of bias.

 

Allocation

In the majority of studies randomization was described as being performed using either a random number table or a computer-generated random number schedule (Blanch 1998; Bréart 1992; Cluett 2004; Frigoletto 1995; Lopez-Zeno 1992; Nachum 2010; Rogers 1997; Sadler 2000; Somprasit 2005; Tabowei 2003). In two studies the method of randomization was not reported (Cammu 1996; Snehlata 2011). In one study alternation was used (Cohen 1987) and in another study randomization was based on the last digit of the medical notes (Serman 1995). Randomization was concealed in 11 out of the 14 studies contributing data to the meta-analysis (Blanch 1998; Bréart 1992; Cammu 1996; Cluett 2004; Frigoletto 1995; Lopez-Zeno 1992; Nachum 2010; Rogers 1997; Sadler 2000; Somprasit 2005; Tabowei 2003). In one study (Serman 1995), the method of allocation was based on the woman's medical file number (odd or even numbers). In another study (Cohen 1987), women were allocated by alternate assignment. Allocation concealment, when performed, was achieved by telephone in one trial (Frigoletto 1995), and by sealed envelopes in the remaining studies.

 

Blinding

Amniotomy is virtually impossible to mask, and oxytocin was not blinded in the trials. Therefore, in all the studies, the participants and clinicians were not blinded to the treatment, the risks of bias were high.

 

Incomplete outcome data

Most studies were at low risk of bias. In the Frigoletto 1995 trial, one-third of the women became ineligible for the study between randomization and the onset of labour because they developed medical complications or their labour was induced with oxytocin. In one trial (Sadler 2000), the overall response rate to the maternal satisfaction questionnaire was 72% (28% attrition).

 

Selective reporting

Most studies reported the main outcomes. In the Frigoletto 1995 trial, one-third of the women became ineligible for the study between randomization and the onset of labour, since post-randomization attrition is likely to introduce bias, we only included the CS data from this study as it was the only outcome that was reported in an intention-to-treat analysis. In one trial (Snehlata 2011), there is only abstract information available; only CS and duration of labour were available.

 

Other potential sources of bias

In one study (Blanch 1998), the data on the number of women eligible for the trial were not available. The trial was stopped early with only half of the women recruited due to slow recruitment rate. In the Frigoletto 1995 trial, the protocol was changed during the study.

 

Effects of interventions

There was evidence of statistical heterogeneity for the following outcomes: the length of the first stage of labour (I² = 79%),  Analysis 1.4; the overall duration of labour (I² = 94%),  Analysis 1.5; and use of epidural analgesia in the therapy (I² = 52%),  Analysis 1.6; test for subgroup differences in postpartum haemorrhage(I² = 49%),  Analysis 1.8; maternal blood transfusion (I² = 49%),  Analysis 1.9. For the sensitivity analyses, length of first stage of labour (I² = 75%),  Analysis 2.4; duration of labour (I² = 86%),  Analysis 2.5; use of epidural analgesia in the therapy (I² = 52%),  Analysis 2.6; postpartum haemorrhage (I² = 47%),  Analysis 2.7; maternal blood transfusion (I² = 49%),  Analysis 2.8; postpartum fever or infection (I² = 32%),  Analysis 2.9; admission to special care nursery (I² = 39%),  Analysis 2.14.

 

Primary outcome

In the unstratified analysis, the point estimate for CS suggested a modest reduction with early amniotomy and oxytocin although the confidence interval (CI) included null effect (average risk ratio (RR) 0.89; 95% CI 0.79 to 1.01),  Analysis 1.1. In the stratified analysis, for prevention trials early augmentation was associated with a modest reduction in the CS rate (average RR 0.87; 95% CI 0.77 to 0.99),  Analysis 1.1.1. The difference in caesarean risk was 0.02. The number of women needed to treat (NNT) to prevent one CS was approximately 65. This conclusion is based on 11 randomized controlled trials involving 7653 women. In contrast, there was no statistical evidence of such an effect in therapy trials (average RR 1.47; 95% CI 0.73 to 2.96),  Analysis 1.1.2. However, the number of therapy trials was small (three trials involving 280 women). An interaction test (Breslow -Day test) between prevention and therapy groups for CS, showed a Chi² value was 2.08, P = 0.15. Thus, there was no statistical evidence of an interaction between treatment effect and trial type (prevention versus therapy); however, the statistical power of this test was low. In a sensitivity analysis, we excluded the four prevention trials where the experimental intervention consisted of the full active management package. Results revealed that the effect estimate was not modified by excluding these four trials (unstratified analysis: average RR 0.87; 95% CI 0.73 to 1.05; prevention trials: average RR 0.84; 95% CI 0.70 to 1.01),  Analysis 2.1.

 

Secondary outcomes

The length of first stage of labour was shortened in the early amniotomy and oxytocin group compared with the expectant management group (average mean difference (MD) -1.57 hours; 95% CI -2.14 to -1.01; random effects, T² = 0.32, I² = 79%),  Analysis 1.4. In the stratified analysis, the effect of the study group on the duration of the first stage of labour was most marked in the prevention trials (average MD -1.57 hours; 95% CI -2.15 to -1.00; random effects, T² = 0.26, I² = 82%),  Analysis 1.41. There was also statistical evidence of such an effect in the therapy trials (average MD -1.58 hours; 95% CI -4.27 to 1.10; random effects, T² = 3.21, I² = 85%),  Analysis 1.4.2.

Eight trials reported duration of labour (admission to delivery interval) (mean±standard deviation). Overall, early amniotomy and oxytocin was associated with a reduction in the duration of labour (average MD -1.28 hours; 95% CI -1.97 to - 0.59; random effects, T² = 0.83, I² = 94%),  Analysis 1.5. However, there was significant heterogeneity across the studies, even when using standardized mean difference instead of mean difference (I² = 94%).

As for other maternal outcomes such as spontaneous delivery (RR 1.01; 95% CI 0.97 to 1.05),  Analysis 1.2, instrumental vaginal delivery (RR 1.01; 95% CI 0.92 to 1.12),  Analysis 1.3 and use of epidural analgesia (average RR 1.05; 95% CI 0.99 to 1.11),  Analysis 1.6, there was no evidence of an effect on early amniotomy and oxytocin. Three trials (Bréart 1992; Cammu 1996; Lopez-Zeno 1992) reported on the frequency of requirement for maternal blood transfusion. A trend towards an increase in transfusion was noted (average RR 1.84; 95% CI 0.32 to 10.84),  Analysis 1.9, in association with early intervention. This effect was mainly due to one study (Bréart 1992). There was no evidence of an effect of early intervention on a range of adverse maternal outcome indicators including hyperstimulation of labour, postpartum haemorrhage (greater than 500 ml), maternal blood transfusion, or postpartum fever or infection.

The relative risk for a number of indicators of fetal/infant morbidity and mortality (Apgar less than seven at five minutes; abnormal arterial blood cord pH (pH less than 7.10 or 7.20); suboptimal or abnormal fetal heart tracing; fetal distress; admission to special care nursery; seizure/neurological abnormalities; or jaundice or hyperbilirubinaemia) showed no evidence of differences between early amniotomy and oxytocin groups and control groups,  Analysis 1.11;  Analysis 1.12;  Analysis 1.13;  Analysis 1.14;  Analysis 1.15;  Analysis 1.16;  Analysis 1.17.

Three studies assessed the effects of the policy of early amniotomy and oxytocin on subjective indicators. Three trials (Bréart 1992; Cluett 2004; Sadler 2000) asked women about their overall satisfaction with the care they received. In one study (Bréart 1992), a majority of mothers rated their experience of delivery as satisfactory or unsatisfactory, with similar levels of satisfaction reported in both groups (RR 1.01; 95% CI 0.99 to 1.04). In another trial (Cluett 2004), the proportion of women that indicated that they were satisfied with their labour experience was similar in two groups (RR 1.02; 95% CI 0.75 to 1.39). In the trial (Sadler 2000), the proportion of women reporting that they were very satisfied was also similar in the two groups (RR 1.04; 95% CI 0.94 to 1.15). However, there was a higher proportion of non-responders in the control group. When results were summarized across trials, there was no difference between groups in the proportion who indicated that they were satisfied with their labour experience (RR 1.02; 95% CI 0.99 to 1.04),  Analysis 1.18.

In the sensitivity analyses, we excluded the four prevention trials where the experimental intervention consisted of the full active management package. Results revealed that the effects estimate of the secondary outcomes were not modified,  Analysis 2.2 to  Analysis 2.6;  Analysis 2.7 to  Analysis 2.17.

 

Discussion

  1. Top of page
  2. Background
  3. Objectives
  4. Methods
  5. Results
  6. Discussion
  7. Authors' conclusions
  8. Acknowledgements
  9. Data and analyses
  10. Appendices
  11. What's new
  12. History
  13. Contributions of authors
  14. Declarations of interest
  15. Sources of support
  16. Index terms

The main finding of this systematic review suggests that a policy of early intervention with amniotomy and oxytocin, when applied in the context of a prevention strategy for women in normal spontaneous labour with mild delays in progress, may result in a clinically modest reduction in the rate of caesarean section. A labour shortening effect was observed consistently across trials. In prevention trials, there was estimated 70-minute reduction in the duration of labour. While labour shortening could be viewed as a desirable effect, little information is available concerning women's views on this effect. More information is required about women's perceptions of early intervention, and the effects of early intervention on pain during labour.

A major shortcoming of several of these studies was their difficulty in obtaining a contrast between treatment groups in the interventions provided. Obstetricians who have strong beliefs about the efficacy of routine methods of care may have difficulty in attaining the equipoise that is required to achieve the desired degree of contrast in the interventions administered (Klein 1995). With respect to outcomes, when a policy designed to reduce caesarean rates is implemented for women in the experimental arm of a trial, it is likely to impact on care providers attitudes concerning the use of caesarean in the control arm. Cluster-randomized designs, where centres are allocated either to the implementation of a new policy or to usual care, could provide a partial solution to these problems. This design would permit researchers to undertake efforts to optimise compliance while minimising contamination.

Active management of labour protocol (O'Driscoll 1970) consists of an accurate diagnosis of labour, early amniotomy, frequent vaginal examinations, high dose oxytocin augmentation for slow labour progress (cervical dilatation less than 1 cm/hour), and continuous professional social support. Early amniotomy and oxytocin are two key components of active management. This meta-analysis included four trials where the experimental intervention consisted of the full package of active management of labour (Frigoletto 1995; Rogers 1997; Snehlata 2011; Tabowei 2003).

Concerning other indicators of maternal and neonatal morbidity, we found no evidence of an effect.

We wanted to assess whether the observed effect on caesarean section would be altered when we excluded studies of the active management of labour that included the full package of components making up this intervention. To this end, we conducted a sensitivity analysis by excluding four such trials. The direction and the magnitude of the effect of the point estimates were similar, irrespective of whether these three trials were included or not.

Over the past several years, a number of randomized clinical trials have assessed the effectiveness of the components of active management, either alone or in combination. A Cochrane review assessing the effects of early amniotomy as an isolated intervention has been published (Smyth 2007). It found that amniotomy was associated with an increased risk of delivery by caesarean section compared with women in the control group, although the difference was not statistically significant. Few randomized studies have been designed to assess oxytocin as an isolated intervention (Bidgood 1987; Hinshaw 2008). We are unaware of any systematic review assessing this specific component of active management. Other aspects of active management have also been studied separately: continuous support in labour has been found to be associated with a small but statistically significant reduction in caesarean risk (Hodnett 2011). A recent Cochrane review examines the effect of active management (as a package of care) on the rate of caesarean (Brown 2008). It found that active management is associated with modest reductions in the caesarean section rate. Our review, which assessed early augmentation with amniotomy and oxytocin for women in spontaneous labour, showed that early amniotomy and oxytocin applied in the context of a prevention strategy for women in normal spontaneous labour or with mild delays in progress, may result in a clinically modest reduction in the rate of caesarean section. It is of interest that when early amniotomy is performed alone, it seems to increase the risk of caesarean. When combined with oxytocin, it appears to have a protective effect. There is a need for better information about the effect of oxytocin alone.

In 1998, we published a systematic review of the effects of early augmentation of labour in nulliparous women (Fraser 1998). The direction and magnitude of the observed effect was similar to that in the current review: a small reduction in the risk of caesarean section was observed, but the 95% confidence interval included the null effect. The current review adds several new studies which results in narrower confidence intervals and a change in the conclusion of the meta-analysis. In the stratified analysis, for prevention trials, early augmentation was associated with a modest reduction in the caesarean section rate with the 95% confidence interval excluding the null effect. We believe that the stratified results can be considered separately from the overall results, in that we planned a priori to test our hypothesis in both the prevention and treatment strata. Furthermore, the context of care is somewhat different between prevention and treatment trials.

A limitation of this review is the lack of documentation from most trials relating to other aspects of care during childbirth, such as continuous professional support, mobility and positions during labour. It was difficult to determine how these co-interventions interact with the medical components of active management (early amniotomy and oxytocin) and their impact on clinical outcomes. Also, the degree of delay, that justified the use of oxytocin, varied across trials. Additionally, the criteria of 'treatment failure' (duration of cervical arrest following oxytocin treatment which justifies a caesarean section) were not standardized. It is highly plausible that standard diagnostic for 'treatment failure' could contribute to reducing the caesarean section rate.

In summary, data from the meta-analysis indicate that a policy of early routine augmentation for mild delay in labour progress results in a modest reduction of caesarean section rate. The severity of delay which is sufficient to justify intervention remains to be defined.

 

Authors' conclusions

  1. Top of page
  2. Background
  3. Objectives
  4. Methods
  5. Results
  6. Discussion
  7. Authors' conclusions
  8. Acknowledgements
  9. Data and analyses
  10. Appendices
  11. What's new
  12. History
  13. Contributions of authors
  14. Declarations of interest
  15. Sources of support
  16. Index terms

 

Implications for practice

These data suggest that early labour augmentation, when used in a context similar to that seen in prevention trials, results in a modest reduction in caesarean section rate in nulliparous women. These interventions are the main medical interventions included in the active management of labour: a complex protocol that traditionally included, in addition to amniotomy and oxytocin, the prospective diagnosis of labour, continuous professional social support, limited use of epidural anaesthesia, maternal ambulation in early labour, and the selective use of electronic fetal monitoring. The approach to these co-interventions are likely to impact on the overall effects of such a program. Centres that opt to implement a policy of early labour augmentation should carefully consider their policies concerning these other aspects of labour management. Given widespread concerns regarding increasing caesarean section rates, women should be informed of the possible benefits of early intervention by amniotomy and oxytocin to reduce caesarean section, and of the apparent relative safety of the procedure.

 
Implications for research

Further studies are required to assess the risks and benefits of active management. Standardization of diagnostic criteria regarding the degree of delay following treatment that is sufficient to justify a caesarean section needs further consideration. A period of two hours of observation after oxytocin, as reported in the Lopez-Zeno study (Lopez-Zeno 1992) may not be sufficient to judge treatment response, particularly in the low-dose oxytocin group. Limited information is available on the mothers' views of the two approaches to treatment.

Subsequent studies should focus on the effects of early labour augmentation versus expectant management among two specific contexts of increased caesarean rate: (1) where risk status is based on an established delay in labour progress, or on other characteristics which place the women at an increased risk (cervical status at admission) (Turcot 1997); (2) where risk status is based on the practice patterns of the care providers. We suggest that a cluster-randomization design may be the best methodology to assess the benefits of early augmentation in the latter context of increased risk.

In most adequately resourced centres, oxytocin augmentation is accompanied by continuous electronic fetal monitoring. One study (Tabowei 2003), conducted in Nigeria, did not report on the approach to fetal monitoring that was used. The results of this review cannot be generalized to settings where electronic fetal monitoring is not available.

It would be important to undertake an economic analysis in order to compare costs between active management of labour versus standard treatment. Early oxytocin use without rupture of membranes should be the subject of another Cochrane review. An additional key issue is the recommendation to avoid early artifical rupture of the membranes among patients who are HIV positive in order to prevent viral transmission. This is especially important in developing countries where a high proportion of women are HIV positive.

 

Acknowledgements

  1. Top of page
  2. Background
  3. Objectives
  4. Methods
  5. Results
  6. Discussion
  7. Authors' conclusions
  8. Acknowledgements
  9. Data and analyses
  10. Appendices
  11. What's new
  12. History
  13. Contributions of authors
  14. Declarations of interest
  15. Sources of support
  16. Index terms

During the study, Dr Fraser was supported by a Canada Research Chair in Perinatal Epidemiology, from the Canadian Institutes of Health Research (CIHR). Drs Shuqin Wei and Hairong Xu are supported by a Scholarship from the CIHR Strategic Training Initiative in Research in Reproductive Health Sciences (STIRRHS). Dr Luo is supported by a Junior Scholar award from the Quebec Foundation of Health Research (FRSQ).

The 2013 updated review was financially supported by the UNDP-UNFPA-UNICEF-WHO-World Bank Special Programme of Research, Development and Research Training in Human Reproduction (HRP), the Department of Reproductive Health and Research (RHR), World Health Organization. The named authors alone are responsible for the views expressed in this publication.

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.

 

Data and analyses

  1. Top of page
  2. Background
  3. Objectives
  4. Methods
  5. Results
  6. Discussion
  7. Authors' conclusions
  8. Acknowledgements
  9. Data and analyses
  10. Appendices
  11. What's new
  12. History
  13. Contributions of authors
  14. Declarations of interest
  15. Sources of support
  16. Index terms
Download statistical data

 
Comparison 1. Early amniotomy and early oxytocin versus routine care on spontaneous labour

Outcome or subgroup titleNo. of studiesNo. of participantsStatistical methodEffect size

 1 Caesarean section rate148033Risk Ratio (M-H, Random, 95% CI)0.89 [0.79, 1.01]

    1.1 Prevention
117753Risk Ratio (M-H, Random, 95% CI)0.87 [0.77, 0.99]

    1.2 Therapy
3280Risk Ratio (M-H, Random, 95% CI)1.47 [0.73, 2.96]

 2 Spontaneous vaginal delivery126020Risk Ratio (M-H, Fixed, 95% CI)1.01 [0.97, 1.05]

    2.1 Prevention
95738Risk Ratio (M-H, Fixed, 95% CI)1.01 [0.97, 1.05]

    2.2 Therapy
3282Risk Ratio (M-H, Fixed, 95% CI)0.96 [0.85, 1.08]

 3 Instrumental vaginal delivery (forceps or vacuum, or both)126018Risk Ratio (M-H, Fixed, 95% CI)1.01 [0.92, 1.12]

    3.1 Prevention
95738Risk Ratio (M-H, Fixed, 95% CI)1.01 [0.92, 1.11]

    3.2 Therapy
3280Risk Ratio (M-H, Fixed, 95% CI)1.32 [0.55, 3.13]

 4 Length of first stage of labour62671Mean Difference (IV, Random, 95% CI)-1.57 [-2.14, -1.01]

    4.1 Prevention
42431Mean Difference (IV, Random, 95% CI)-1.57 [-2.15, 1.00]

    4.2 Therapy
2240Mean Difference (IV, Random, 95% CI)-1.58 [-4.27, 1.10]

 5 Duration of labour (duration in hours from admission in labour)84816Mean Difference (IV, Random, 95% CI)-1.28 [-1.97, -0.59]

    5.1 Prevention
74675Mean Difference (IV, Random, 95% CI)-1.11 [-1.82, -0.41]

    5.2 Therapy
1141Mean Difference (IV, Random, 95% CI)-3.10 [-4.63, -1.57]

 6 Use of epidural analgesia94460Risk Ratio (M-H, Random, 95% CI)1.05 [0.99, 1.11]

    6.1 Prevention
64180Risk Ratio (M-H, Random, 95% CI)1.05 [0.99, 1.10]

    6.2 Therapy
3280Risk Ratio (M-H, Random, 95% CI)1.02 [0.66, 1.59]

 7 Hyperstimulation of labour2853Risk Ratio (M-H, Random, 95% CI)1.37 [0.76, 2.46]

    7.1 Prevention
2853Risk Ratio (M-H, Random, 95% CI)1.37 [0.76, 2.46]

   7.2 Therapy
00Risk Ratio (M-H, Random, 95% CI)0.0 [0.0, 0.0]

 8 Postpartum haemorrhage (greater than 500 ml)52815Risk Ratio (M-H, Fixed, 95% CI)0.86 [0.67, 1.11]

    8.1 Prevention
42674Risk Ratio (M-H, Fixed, 95% CI)0.83 [0.65, 1.08]

    8.2 Therapy
1141Risk Ratio (M-H, Fixed, 95% CI)6.90 [0.36, 131.23]

 9 Maternal blood transfusion32977Risk Ratio (M-H, Random, 95% CI)1.84 [0.32, 10.48]

    9.1 Prevention
32977Risk Ratio (M-H, Random, 95% CI)1.84 [0.32, 10.48]

   9.2 Therapy
00Risk Ratio (M-H, Random, 95% CI)0.0 [0.0, 0.0]

 10 Postpartum fever or infection62923Risk Ratio (M-H, Random, 95% CI)0.90 [0.69, 1.17]

    10.1 Prevention
52824Risk Ratio (M-H, Random, 95% CI)0.88 [0.66, 1.16]

    10.2 Therapy
199Risk Ratio (M-H, Random, 95% CI)1.63 [0.41, 6.47]

 11 Apgar score less than seven at five minutes74519Risk Ratio (M-H, Fixed, 95% CI)1.11 [0.78, 1.57]

    11.1 Prevention
64479Risk Ratio (M-H, Fixed, 95% CI)1.10 [0.77, 1.55]

    11.2 Therapy
140Risk Ratio (M-H, Fixed, 95% CI)2.73 [0.12, 63.19]

 12 Acidosis as defined abnormal arterial cord pH (pH less than 7.10 or 7.20)31416Risk Ratio (M-H, Fixed, 95% CI)1.11 [0.61, 2.02]

    12.1 Prevention
31416Risk Ratio (M-H, Fixed, 95% CI)1.11 [0.61, 2.02]

   12.2 Therapy
00Risk Ratio (M-H, Fixed, 95% CI)0.0 [0.0, 0.0]

 13 Suboptimal or abnormal fetal heart tracing1705Risk Ratio (M-H, Random, 95% CI)0.50 [0.13, 2.00]

    13.1 Prevention
1705Risk Ratio (M-H, Random, 95% CI)0.50 [0.13, 2.00]

   13.2 Therapy
00Risk Ratio (M-H, Random, 95% CI)0.0 [0.0, 0.0]

 14 Fetal distress21099Risk Ratio (M-H, Fixed, 95% CI)1.22 [0.55, 2.69]

    14.1 Prevention
21099Risk Ratio (M-H, Fixed, 95% CI)1.22 [0.55, 2.69]

   14.2 Therapy
00Risk Ratio (M-H, Fixed, 95% CI)0.0 [0.0, 0.0]

 15 Admission to special care nursery74578Risk Ratio (M-H, Random, 95% CI)1.05 [0.77, 1.43]

    15.1 Prevention
64479Risk Ratio (M-H, Random, 95% CI)1.13 [0.91, 1.41]

    15.2 Therapy
199Risk Ratio (M-H, Random, 95% CI)0.08 [0.00, 1.30]

 16 Seizure/neurological abnormalities22666Risk Ratio (M-H, Fixed, 95% CI)0.83 [0.25, 2.71]

    16.1 Prevention
22666Risk Ratio (M-H, Fixed, 95% CI)0.83 [0.25, 2.71]

   16.2 Therapy
00Risk Ratio (M-H, Fixed, 95% CI)0.0 [0.0, 0.0]

 17 Jaundice or hyperbilirubinemia22219Risk Ratio (M-H, Fixed, 95% CI)1.10 [0.68, 1.77]

    17.1 Prevention
22219Risk Ratio (M-H, Fixed, 95% CI)1.10 [0.68, 1.77]

   17.2 Therapy
00Risk Ratio (M-H, Fixed, 95% CI)0.0 [0.0, 0.0]

 18 Satisfied with labour experience32618Risk Ratio (M-H, Fixed, 95% CI)1.02 [0.99, 1.04]

    18.1 Prevention
22436Risk Ratio (M-H, Fixed, 95% CI)1.02 [0.99, 1.04]

    18.2 Therapy
1182Risk Ratio (M-H, Fixed, 95% CI)1.02 [0.75, 1.39]

 
Comparison 2. Early amniotomy and early oxytocin versus routine care on spontaneous labour (Sensitivity analyses: active management trials excluded)

Outcome or subgroup titleNo. of studiesNo. of participantsStatistical methodEffect size

 1 Caesarean section rate105165Risk Ratio (M-H, Random, 95% CI)0.87 [0.73, 1.05]

    1.1 Prevention
74885Risk Ratio (M-H, Random, 95% CI)0.84 [0.70, 1.01]

    1.2 Therapy
3280Risk Ratio (M-H, Random, 95% CI)1.47 [0.73, 2.96]

 2 Spontaneous vaginal delivery105167Risk Ratio (M-H, Fixed, 95% CI)1.02 [0.98, 1.05]

    2.1 Prevention
74885Risk Ratio (M-H, Fixed, 95% CI)1.02 [0.98, 1.06]

    2.2 Therapy
3282Risk Ratio (M-H, Fixed, 95% CI)0.96 [0.85, 1.08]

 3 Instrumental vaginal delivery (forceps or vacuum, or both)105165Risk Ratio (M-H, Fixed, 95% CI)1.01 [0.91, 1.12]

    3.1 Prevention
74885Risk Ratio (M-H, Fixed, 95% CI)1.00 [0.90, 1.11]

    3.2 Therapy
3280Risk Ratio (M-H, Fixed, 95% CI)1.32 [0.55, 3.13]

 4 Length of first stage of labour41818Mean Difference (IV, Random, 95% CI)-1.38 [-2.20, -0.56]

    4.1 Prevention
21578Mean Difference (IV, Random, 95% CI)-1.27 [-2.08, -0.47]

    4.2 Therapy
2240Mean Difference (IV, Random, 95% CI)-1.58 [-4.27, 1.10]

 5 Duration of labour (duration in hours from admission in labour)63963Mean Difference (IV, Random, 95% CI)-1.02 [-1.62, -0.41]

    5.1 Prevention
53822Mean Difference (IV, Random, 95% CI)-0.81 [-1.36, -0.25]

    5.2 Therapy
1141Mean Difference (IV, Random, 95% CI)-3.10 [-4.63, -1.57]

 6 Use of epidural analgesia84055Risk Ratio (M-H, Random, 95% CI)1.04 [0.97, 1.11]

    6.1 Prevention
53775Risk Ratio (M-H, Random, 95% CI)1.04 [0.98, 1.10]

    6.2 Therapy
3280Risk Ratio (M-H, Random, 95% CI)1.02 [0.66, 1.59]

 7 Postpartum haemorrhage (greater than 500 ml)31962Risk Ratio (M-H, Random, 95% CI)0.92 [0.59, 1.43]

    7.1 Prevention
21821Risk Ratio (M-H, Random, 95% CI)0.88 [0.60, 1.28]

    7.2 Therapy
1141Risk Ratio (M-H, Random, 95% CI)6.90 [0.36, 131.23]

 8 Maternal blood transfusion32977Risk Ratio (M-H, Random, 95% CI)1.84 [0.32, 10.48]

    8.1 Prevention
32977Risk Ratio (M-H, Random, 95% CI)1.84 [0.32, 10.48]

   8.2 Therapy
00Risk Ratio (M-H, Random, 95% CI)0.0 [0.0, 0.0]

 9 Postpartum fever or infection42070Risk Ratio (M-H, Random, 95% CI)0.93 [0.56, 1.55]

    9.1 Prevention
31971Risk Ratio (M-H, Random, 95% CI)0.87 [0.48, 1.58]

    9.2 Therapy
199Risk Ratio (M-H, Random, 95% CI)1.63 [0.41, 6.47]

 10 Apgar score less than seven after five minutes53666Risk Ratio (M-H, Fixed, 95% CI)1.18 [0.61, 2.29]

    10.1 Prevention
43626Risk Ratio (M-H, Fixed, 95% CI)1.13 [0.57, 2.22]

    10.2 Blanch
140Risk Ratio (M-H, Fixed, 95% CI)2.73 [0.12, 63.19]

 11 Acidosis as defined abnormal arterial cord pH (pH less than 7.10 or 7.20)21011Risk Ratio (M-H, Fixed, 95% CI)1.12 [0.60, 2.10]

    11.1 Prevention
21011Risk Ratio (M-H, Fixed, 95% CI)1.12 [0.60, 2.10]

   11.2 Therapy
00Risk Ratio (M-H, Fixed, 95% CI)0.0 [0.0, 0.0]

 12 Suboptimal or abnormal fetal heart1705Risk Ratio (M-H, Fixed, 95% CI)0.50 [0.13, 2.00]

 13 Fetal distress1651Risk Ratio (M-H, Fixed, 95% CI)1.03 [0.26, 4.10]

 14 Admission to special care nursery53725Risk Ratio (M-H, Random, 95% CI)1.01 [0.65, 1.57]

    14.1 Prevention
43626Risk Ratio (M-H, Random, 95% CI)1.15 [0.89, 1.50]

    14.2 Therapy
199Risk Ratio (M-H, Random, 95% CI)0.08 [0.00, 1.30]

 15 Seizure/neurological abnormalities22666Risk Ratio (M-H, Fixed, 95% CI)0.83 [0.25, 2.71]

 16 Jaundice or hyperbilirubinemia22219Risk Ratio (M-H, Fixed, 95% CI)1.10 [0.68, 1.77]

 17 Satisfied with labour experience32618Risk Ratio (M-H, Fixed, 95% CI)1.02 [0.99, 1.04]

 

Appendices

  1. Top of page
  2. Background
  3. Objectives
  4. Methods
  5. Results
  6. Discussion
  7. Authors' conclusions
  8. Acknowledgements
  9. Data and analyses
  10. Appendices
  11. What's new
  12. History
  13. Contributions of authors
  14. Declarations of interest
  15. Sources of support
  16. Index terms
 

Appendix 1. Search strategy

MEDLINE (1966 to 4 July 2013), Embase (1980 to 4 July 2013), CINAHL (1982 to 4 July 2013) and MIDIRS (1985 to 4 July 2012)

#1 Oxytocin/ OR oxytoc$
#2 amniotom$
#3 #1 AND #2

 

Appendix 2. Methods used to assess trials included in previous versions of this review

The following methods were used to assess Blanch 1998; Bréart 1992; Cammu 1996; Cluett 2004; Cohen 1987; Frigoletto 1995; Lopez-Zeno 1992; Rogers 1997; Sadler 2000; Serman 1995; Somprasit 2005; Tabowei 2003; Cardozo 1990; Cummiskey 1989; Hogston 1993; Rouse 1994; Ruiz Ortiz 1991; Verkuyl 1986; Xenakis 1995.

 

Data collection and analysis  

 

Selection of studies  

Two review authors (SQ Wei and BL Wo) independently assessed for inclusion all potential studies we identified as a result of the search strategy. We excluded studies where women in both treatment groups underwent amniotomy. We resolved any disagreement through discussion or consulted a third author (WD Fraser).

 

Data extraction and management  

We designed a form to extract data. For eligible studies, at least two review authors (SQ Wei, BL Wo or ZC Luo) extracted the data independently. We resolved discrepancies through discussion or consulted a third author (WDF). We entered data into Review Manager software (RevMan 2008) and checked them for accuracy.

When information regarding any of the above was unclear, we attempted to contact authors of the original reports to provide further details.

 

Assessment of risk of bias in included studies  

Two review authors (SQ Wei and HR Xu) independently assessed risk of bias for each study using the criteria outlined in the Cochrane Handbook for Systematic Reviews of Interventions (Higgins 2008). Any disagreement was resolved by discussion or by involving a third author (WD Fraser).

 

(1) 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:

  • adequate (any truly random process e.g. random number table; computer random number generator);
  • inadequate (any non random process, e.g., odd or even date of birth; hospital; or clinic record number); or
  • unclear.

 

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

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

We assessed the methods as:

  • adequate (e.g., telephone or central randomisation; consecutively numbered sealed opaque envelopes);
  • inadequate (open random allocation;unsealed or non-opaque envelopes; alternation; date of birth);
  • unclear.

 

(3) Blinding (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 have noted where blinding was not possible or was not used (and this is likely to be the case in interventions where different styles of care were compared).

We assessed the methods as:
(1) adequate, inadequate or unclear for participants;
(2) adequate, inadequate or unclear for personnel;
(3) adequate, inadequate or unclear for outcome assessors.

 

(4) Incomplete outcome data (checking for possible attrition bias through withdrawals, dropouts, protocol deviations)

We have described for each included study the completeness of outcome data for each main outcome, including attrition and exclusions from the analysis. We have stated whether attrition and exclusions were reported, the numbers (compared with the total randomised participants), reasons for attrition/exclusion where reported, and whether missing data were balanced across groups. Where sufficient information is reported, we re-included missing data in the analyses which we have undertaken.

We have assessed the methods as:

  • adequate (e.g., where there was no missing data or low levels of missing data, and where reasons for missing data were balanced across groups);
  • inadequate (e.g., where there were high levels of missing data or where attrition was not balanced across groups);
  • unclear (e.g., where there was insufficient reporting of attrition or exclusions to permit a judgement to be made).

(For outcomes measured in labour, we would expect low levels of missing data to be no more than 10%.)

 

(5) Selective 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:

  • adequate (e.g., 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);
  • inadequate (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 could not be used; study failed to include results of a key outcome that would have been expected to have been reported);
  • unclear.

 

(6) Other sources of bias

We have described for each included study any important concerns we had about other possible sources of bias; for example, where there was a potential source of bias related to the specific study design; where the protocol changed part-way through; where there was extreme baseline imbalance; or where the study had been claimed to be fraudulent.

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

  • yes;
  • no;
  • unclear.

 

(7) Overall risk of bias

We had made explicit judgements about risk of bias for important outcomes both within and across studies. With reference to (1) to (6) above, we have assessed the likely magnitude and direction of the bias and whether we considered it was likely to impact on findings.

 

Measures of treatment effect  

 

Dichotomous data

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

 

Continuous data

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

 

Cluster-randomised trials

We did not identify any cluster-randomised trials on this topic.

 

Dealing with missing data  

For included studies, we have noted levels of attrition.

We analyzed 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.

 

Assessment of heterogeneity  

We applied tests of heterogeneity between trials, if appropriate, using the I2 statistic. If we identified high levels of heterogeneity among the trials (exceeding 50%), a random-effects meta-analysis was used as an overall summary.

 

Assessment of reporting biases  

Where we suspected reporting bias or where missing data were thought to introduce serious bias, this has been reported.

 

Data synthesis  

We carried out statistical analysis using RevMan 2008. We used fixed-effect inverse variance meta-analysis for combining data where trials are examining 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 might differ between trials, we used random-effects meta-analysis.

If substantial heterogeneity was identified in a fixed effect meta-analysis, the analysis was repeated using a random-effects method.

 

Subgroup analysis and investigation of heterogeneity  

We conducted the following subgroup analyses:

  1. 'Prevention Trials' ,which were defined as trials that included unselected women in early spontaneous labour who were allocated to either early amniotomy and oxytocin in the case of delay in progress, or to usual care.
  2. 'Therapy Trials' , which were defined as trials that only included women with an established delay in labour progress. In these trials, women had been allocated to either early amniotomy and oxytocin, or to routine care.

For fixed effect meta-analyses, we conducted planned subgroup analyses classifying whole trials by interaction tests as described by Deeks 2001. For random effects meta-analyses, we assessed differences between subgroups by inspection of the subgroups' confidence intervals; non-overlapping confidence intervals indicate a statistically significant difference in treatment effect between the subgroups.

 

Sensitivity analysis  

We carried out a sensitivity analysis to explore the effects of a policy of early amniotomy and oxytocin alone, without the full package of co-interventions that are usually considered as constituting active management: continuous professional care, selective admission at the labour ward. Three such studies of active management (Frigoletto 1995; Rogers 1997; Tabowei 2003) were excluded in the sensitivity analysis in order to assess the combined effect of early amniotomy and oxytocin on the primary outcome.

 

What's new

  1. Top of page
  2. Background
  3. Objectives
  4. Methods
  5. Results
  6. Discussion
  7. Authors' conclusions
  8. Acknowledgements
  9. Data and analyses
  10. Appendices
  11. What's new
  12. History
  13. Contributions of authors
  14. Declarations of interest
  15. Sources of support
  16. Index terms

Last assessed as up-to-date: 8 July 2013.


DateEventDescription

29 June 2013New citation required but conclusions have not changedReview updated.

29 June 2013New search has been performedSearch updated. One new report identified and excluded (Yasmin 2002).



 

History

  1. Top of page
  2. Background
  3. Objectives
  4. Methods
  5. Results
  6. Discussion
  7. Authors' conclusions
  8. Acknowledgements
  9. Data and analyses
  10. Appendices
  11. What's new
  12. History
  13. Contributions of authors
  14. Declarations of interest
  15. Sources of support
  16. Index terms

Protocol first published: Issue 4, 2007
Review first published: Issue 2, 2009


DateEventDescription

21 May 2012New citation required but conclusions have not changedTwo new studies added, but conclusions unchanged.

27 February 2012New search has been performedSearch updated. We have assessed the five trial reports previously awaiting classification.

15 February 2012AmendedSearch updated. Five. trial reports added to Studies awaiting classification (Gagnon-Gervais 2011a; Garmi 2008a; Nachum 2010a; Selo-Ojeme 2009a; Snehlata, 2011a).

12 November 2008AmendedConverted to new review format.



 

Contributions of authors

  1. Top of page
  2. Background
  3. Objectives
  4. Methods
  5. Results
  6. Discussion
  7. Authors' conclusions
  8. Acknowledgements
  9. Data and analyses
  10. Appendices
  11. What's new
  12. History
  13. Contributions of authors
  14. Declarations of interest
  15. Sources of support
  16. Index terms

Shuqin Wei: assessed the studies for inclusion; evaluated the study quality; extracted the data; wrote the review; co-ordinated the review; finalized the review in response to the feedback.
Bi Lan Wo: assessed the studies for inclusion; extracted the data;and partially wrote the review.
Hui-Ping Qi: assessed the studies for inclusion; extracted the data; and evaluated the study quality.
Hairong Xu: assessed the studies for inclusion and evaluated the study quality.
Zhong-Cheng Luo: evaluated the study quality, extracted the data and revised the review.
Chantal Roy: collected the relevant publications on this subject and assessed the studies for inclusion.
William D Fraser: conceived the idea for the review; assessed the studies for inclusion; evaluated the study quality; revised the meta-analysis; and is the guarantor for this review.

All the authors, who are named on the 2009 and 2013 updates of the review, approved the final versions.

 

Declarations of interest

  1. Top of page
  2. Background
  3. Objectives
  4. Methods
  5. Results
  6. Discussion
  7. Authors' conclusions
  8. Acknowledgements
  9. Data and analyses
  10. Appendices
  11. What's new
  12. History
  13. Contributions of authors
  14. Declarations of interest
  15. Sources of support
  16. Index terms

William D Fraser is the principal investigator of one of the papers in the meta-analysis.

 

Sources of support

  1. Top of page
  2. Background
  3. Objectives
  4. Methods
  5. Results
  6. Discussion
  7. Authors' conclusions
  8. Acknowledgements
  9. Data and analyses
  10. Appendices
  11. What's new
  12. History
  13. Contributions of authors
  14. Declarations of interest
  15. Sources of support
  16. Index terms
 

Internal sources

  • University of Montreal, Canada.

 

External sources

  • Canadian Institutes of Health Research (CIHR), Canada.
    Dr Fraser is supported by a Canada Research Chair in Perinatal Epidemiology, from the CIHR.
  • CIHR Strategic Training Initiative in Research in Reproductive Health Sciences (STIRRHS), Canada.
    Drs Shuqin Wei and Hairong Xu are supported by a Scholarship from the CIHR Strategic Training Initiative in Research in Reproductive Health Sciences (STIRRHS).
  • Quebec Foundation of Health Research (FRSQ), Canada.
    Dr Luo is supported by a Junior Scholar award.
  • UNDP-UNFPA-UNICEF-WHO-World Bank Special Programme of Research, Development and Research Training in Human Reproduction (HRP), the Department of Reproductive Health and Research (RHR), World Health Organization, Switzerland.

* Indicates the major publication for the study

References

References to studies included in this review

  1. Top of page
  2. AbstractRésumé
  3. Background
  4. Objectives
  5. Methods
  6. Results
  7. Discussion
  8. Authors' conclusions
  9. Acknowledgements
  10. Data and analyses
  11. Appendices
  12. What's new
  13. History
  14. Contributions of authors
  15. Declarations of interest
  16. Sources of support
  17. Characteristics of studies
  18. References to studies included in this review
  19. References to studies excluded from this review
  20. Additional references
  21. References to other published versions of this review
Blanch 1998 {published data only}
Bréart 1992 {published data only}
  • Breart G, Mlika-Cabane N, Kaminski M, Alexander S, Herruzo-Nalda A, Mandruzzato P, et al. Evaluation of different policies for the management of labour. Early Human Development 1992;29(1):309-12.
  • Breart G, Mlika-Cabanne N, Kaminski M. The evaluation of different policies for the management of labour: Trial A. Results of the early amniotomy trial. Proceedings of 3rd European Health Services Research Meeting; 1991; London, UK. 1991.
  • Breart G, Mlika-Cabanne N, Thornton JG, Trakas D, Alexander S, Mandruzzato P, et al. European trials on artificial rupture of membranes and professional support during labour. Trial A: Results of the early amniotomy trial. Journal of Perinatal Medicine 1992;20(1):37.
  • Bréart G, Du Mazaubrun C, Maillard F, Garel M. Comparison of two policies of management of labour for primiparous women: effects of early rupture of membranes and use of oxytocin. Results of randomized controlled trial. Proceedings of International Conference on Primary Care, Obstetrics and Perinatal Health; 1991; Utrecht, Netherlands. 1991:49.
  • Bréart G, Garel M, Mlika-Cabanne N. Evaluation of different policies of management of labour for primiparous women. Trial A: Results of the early amniotomy trial. In: Kaminski M editor(s). Evaluation in pre-, peri-, and post-natal care delivery systems. Paris: INSERM, 1992:43-56.
  • Bréart G, Mlika-Cabanne N, Kaminski M, Alexander S, Herruzo-Nalda A, Mandruzzato P, et al. Peripartum care in EC countries - preliminary results of a European concerted action. Care concern and cure in perinatal medicine. 13th European Congress of Perinatal Medicine; 1992 May; Amsterdam, The Netherlands. 1993:43-56.
Cammu 1996 {published data only}
Cluett 2004 {published data only}
  • Cluett ER, Pickering RM, Brooking JI. An investigation into the feasibility of comparing three management options (augmentation conservative and water) for nulliparae with dystocia in the first stage of labour. Midwifery 2001;17:35-43.
  • Cluett ER, Pickering RM, Getliffe K, Saunders NJ. Randomised controlled trial of labouring in water compared with standard of augmentation for management of dystocia in first stage of labour. BMJ 2004;328:314-8.
Cohen 1987 {published data only}
Frigoletto 1995 {published data only}
Lopez-Zeno 1992 {published data only}
  • Lopez-Zeno JA, Peaceman AM, Adashek JA, Socol ML. A controlled trial of a program for the active management of labor. New England Journal of Medicine 1992;326:450-4.
  • Lopez-Zeno JA, Peaceman AM, Socol ML. Active management of labor (AMOL) - an evaluation of its efficacy. American Journal of Obstetrics and Gynecology 1991;164:306.
  • Peaceman AM, Lopez-Zeno J, Minogue JP, Socol ML. Factors that influence route of delivery - active vs traditional labor management. American Journal of Obstetrics and Gynecology 1993;169:940-4.
Nachum 2010 {published data only}
  • Garmi G, Salim R, Kadan I, Zafran N, Shalev E, Nachum Z. Augmentation of labor for prolonged latent phase at term: a randomized comparison between amniotomy, oxytocin or both. American Journal of Obstetrics & Gynecology 2008;199(6):S58.
  • Nachum Z, Garmi G, Kadan Y, Zafran N, Shalev E, Salim R. Comparison between amniotomy, oxytocin or both for augmentation of labor in prolonged latent phase: a randomized controlled trial. Reproductive Biology and Endocrinology 2010;8:136.
Rogers 1997 {published data only}
Sadler 2000 {published data only}
Serman 1995 {published data only}
  • Serman F, Benavides C, Sandoval J, Pazols R, Bernedo J, Fuenzalida R, et al. Active labour management in primiparas. Prospective study [Revista Chilena de Obstetricia y Ginecologia]. International Journal of Obstetric Anesthesia 1995;60(1):6-11.
Snehlata 2011 {published data only}
  • Snehlata, Sawant V. Comparison of active management of labour versus 'traditional' approach. In: 54th All India Congress of Obstetrics and Gynaecology;2011 January 5-9;Hyderabad, Andhra Pradesh, India. 2011; Vol. 1:246-7.
Somprasit 2005 {published data only}
  • Somprasit C, Tanprasertkul C, Kamudhamas A. Reducing cesarean delivery rates: an active management labor program in a setting with limited resources. Journal of the Medical Association of Thailand 2005;88(1):20-5.
Tabowei 2003 {published data only}
  • Tabowei TO, Oboro VO. Active management of labour in a district hospital setting. Journal of Obstetrics and Gynaecology 2003;23(1):9-12.

References to studies excluded from this review

  1. Top of page
  2. AbstractRésumé
  3. Background
  4. Objectives
  5. Methods
  6. Results
  7. Discussion
  8. Authors' conclusions
  9. Acknowledgements
  10. Data and analyses
  11. Appendices
  12. What's new
  13. History
  14. Contributions of authors
  15. Declarations of interest
  16. Sources of support
  17. Characteristics of studies
  18. References to studies included in this review
  19. References to studies excluded from this review
  20. Additional references
  21. References to other published versions of this review
Cardozo 1990 {published data only}
  • Cardozo L, Pearce M. Oxytocin in active-phase abnormalities of labor: a randomized study. Obstetrics & Gynecology 1990;75:152-7.
  • Cardozo LD. Dysfunctional labour. Proceedings of Silver Jubilee British Congress of Obstetrics and Gynaecology; 1989 July 4-7; London, UK. 1989:76.
Cummiskey 1989 {published data only}
Gagnon-Gervais 2011 {published data only}
  • Gagnon-Gervais K, Iglesias MH, Duperron L, Masse A, Mayrand MH, Sansregret A, et al. Early vs late amniotomy for labor induction: a randomized controlled trial. American Journal of Obstetrics and Gynecology 2011;204(1 Suppl):S127.
Hogston 1993 {published data only}
  • Hogston P, Noble W. Active management of labour - the Portsmouth experience. Journal of Obstetrics and Gynaecology 1993;13:340-2.
Rouse 1994 {published data only}
  • Rouse DJ, McCullough C, Wren A, Owen J, Hauth JC. Active phase arrest: a randomized trial of chorioamnion management. American Journal of Obstetrics and Gynecology 1994;170:376.
  • Rouse DJ, McCullough C, Wren AL, Owen J, Hauth JC. Active-phase labor arrest: a randomized trial of chorioamnion management. Obstetrics & Gynecology 1994;83:937-40.
Ruiz Ortiz 1991 {published data only}
  • Ruiz Ortiz E, Villalobos Roman M, Flores Murrieta G, Sotomayor Alvarado L. Active management of latency labor [Manejo activo del trabajo de parto]. Ginecologia y Obstetricia de Mexico 1991;59:1-7.
Selo-Ojeme 2009 {published data only}
  • Selo-Ojeme DO, Pisal P, Lawal O, Rogers C, Shah A, Sinha S. A randomised controlled trial of amniotomy and immediate oxytocin infusion versus amniotomy and delayed oxytocin infusion for induction of labour at term. Archives of Gynecology & Obstetrics 2009;279(6):813-20.
Verkuyl 1986 {published data only}
  • Verkuyl D, Marks L, Munro H, Bouwmeester A. A randomized double-blind study of the use of oxytocin in non progressing patients in labour. Personal communication 1986.
Xenakis 1995 {published data only}
  • Xenakis EM, Langer O, Piper JM, Conway D, Berkus MD. Low-dose versus high-dose oxytocin augmentation of labor--a randomized trial. American Journal of Obstetrics and Gynecology 1995;173:1874-8.
  • Xenakis EMJ, Field N, Barshes D, Langer O. Efficacy of high dose vs low dose oxytocin in labor augmentation. American Journal of Obstetrics and Gynecology 1994;170:378.
Yasmin 2002 {published data only}
  • Yasmin S, Yasin KF. Nulliparous labour: A trial of early versus delayed use of amniotomy and oxytocin infusion. Medical Forum Monthly 2002;13(9):4-6.

Additional references

  1. Top of page
  2. AbstractRésumé
  3. Background
  4. Objectives
  5. Methods
  6. Results
  7. Discussion
  8. Authors' conclusions
  9. Acknowledgements
  10. Data and analyses
  11. Appendices
  12. What's new
  13. History
  14. Contributions of authors
  15. Declarations of interest
  16. Sources of support
  17. Characteristics of studies
  18. References to studies included in this review
  19. References to studies excluded from this review
  20. Additional references
  21. References to other published versions of this review
Anderson 1989
Betran 2007
Bidgood 1987
Blanks 2003
  • Blanks AM, Vatish M, Allen MJ, Ladds G, de Wit NC, Slater DM, et al. Paracrine oxytocin and estradiol demonstrate a spatial increase in human intrauterine tissues with labor. Journal of Clinical Endocrinology and Metabolism 2003;88(7):3392-400.
Brown 2008
Deeks 2001
  • Deeks JJ, Altman DG, Bradburn MJ. Statistical methods for examining heterogeneity and combining results from several studies in meta-analysis. In: Egger M, Davey Smith G, Altman DG editor(s). Systematic reviews in health care: meta-analysis in context. London: BMJ Books, 2001.
Fraser 1998
Higgins 2008
  • Higgins JPT, Green S, editors. Cochrane Handbook for Systematic Reviews of Interventions Version 5.0.0 [updated February 2008]. The Cochrane Collaboration, 2008. Available from www.cochrane-handbook.org.
Higgins 2011
  • Higgins JPT, Green S, editors. Cochrane Handbook for Systematic Reviews of Interventions Version 5.1.0 [updated March 2011]. The Cochrane Collaboration, 2011. Available from www.cochrane-handbook.org.
Hinshaw 2008
Hodnett 2011
Klein 1995
  • Klein MC, Kaczorowski J, Robbins JM, Gauthier RJ, Jorgensen SH, Joshi AK. Physician's beliefs and behaviour during a randomized controlled trial of episiotomy: consequences for women in their care. Canadian Medical Association Journal 1995;153:769-79.
Liu 2004
  • Liu S, Rusen ID, Joseph KS, Liston R, Kramer MS, Wen SW, et al. Recent trends in caesarean delivery rates and indications for caesarean delivery in Canada. Journal of Obstetrics and Gynaecology Canada: JOGC 2004;26(8):735-42.
NCCWCH 2004
  • National Collaborating Centre for Women's and Children's Health. Caesarean section: clinical guidelines. London: Royal College of Obstetricians and Gynaecology, 2004.
O'Driscoll 1970
  • O'Driscoll K, Jackson RJ, Gallagher JT. Active management of labour and cephalopelvic disproportion. Journal of Obstetrics and Gynaecology of the British Commonwealth 1970;77(5):385-9.
O'Driscoll 1984
Peisner 1986
Philpott 1982
RevMan 2011
  • The Nordic Cochrane Centre, The Cochrane Collaboration. Review Manager (RevMan). 5.1. Copenhagen: The Nordic Cochrane Centre, The Cochrane Collaboration, 2011.
Smyth 2007
Treacy 2006
Turcot 1997
WHO 2000
  • World Health Organization. Managing Complications in Pregnancy and Childbirth. A Guide for Midwives and Doctors. WHO/RHR/00.7. Geneva: WHO, 2000.

References to other published versions of this review

  1. Top of page
  2. AbstractRésumé
  3. Background
  4. Objectives
  5. Methods
  6. Results
  7. Discussion
  8. Authors' conclusions
  9. Acknowledgements
  10. Data and analyses
  11. Appendices
  12. What's new
  13. History
  14. Contributions of authors
  15. Declarations of interest
  16. Sources of support
  17. Characteristics of studies
  18. References to studies included in this review
  19. References to studies excluded from this review
  20. Additional references
  21. References to other published versions of this review
Wei 2009
Wei 2012
  • Wei S, Wo BL, Qi HP, Xu H, Luo ZC, Roy C, Fraser WD. Early amniotomy and early oxytocin for prevention of, or therapy for, delay in first stage spontaneous labour compared with routine care. Cochrane Database of Systematic Reviews 2012, Issue 9. [DOI: 10.1002/14651858.CD006794.pub3]