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Amnioinfusion for third trimester preterm premature rupture of membranes

  1. G Justus Hofmeyr1,*,
  2. Ahizechukwu C Eke2,
  3. Theresa A Lawrie3

Editorial Group: Cochrane Pregnancy and Childbirth Group

Published Online: 30 MAR 2014

Assessed as up-to-date: 2 DEC 2013

DOI: 10.1002/14651858.CD000942.pub3


How to Cite

Hofmeyr GJ, Eke AC, Lawrie TA. Amnioinfusion for third trimester preterm premature rupture of membranes. Cochrane Database of Systematic Reviews 2014, Issue 3. Art. No.: CD000942. DOI: 10.1002/14651858.CD000942.pub3.

Author Information

  1. 1

    University of the Witwatersrand, University of Fort Hare, Eastern Cape Department of Health, Department of Obstetrics and Gynaecology, East London Hospital Complex, East London, Eastern Cape, South Africa

  2. 2

    Michigan State University School of Medicine/Sparrow Hospital, Department of Obstetrics and Gynecology, Lansing, Michigan, USA

  3. 3

    Royal United Hospital, Cochrane Gynaecological Cancer Group, Bath, UK

*G Justus Hofmeyr, Department of Obstetrics and Gynaecology, East London Hospital Complex, University of the Witwatersrand, University of Fort Hare, Eastern Cape Department of Health, Frere and Cecilia Makiwane Hospitals, Private Bag X 9047, East London, Eastern Cape, 5200, South Africa. justhof@gmail.com.

Publication History

  1. Publication Status: New search for studies and content updated (no change to conclusions)
  2. Published Online: 30 MAR 2014

SEARCH

 

Summary of findings    [Explanations]

  1. Top of page
  2. Summary of findings    [Explanations]
  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. Differences between protocol and review
  18. Index terms

 
Summary of findings for the main comparison.

Transabdominal amnioinfusion compared with no amnioinfusion for preterm rupture of membranes (PROM)

Patient or population: pregnant women with PROM

Settings: hospital

Intervention: transabdominal amnioinfusion

Comparison: no amnioinfusion

OutcomesRelative effect
(95% CI)
No of Participants
(studies)
Quality of the evidence
(GRADE)
Comments

Neonatal deathRR 0.30 (0.14 - 0.66)94 (two studies)⊕⊕⊕⊝
moderate
Risk of neonatal death in the amnioinfusion group was 127 per 1000 compared to 426 per 1000 in the control group.

Neonatal sepsis/infectionRR 0.26 (0.11 - 0.61)60 (one study*)⊕⊕⊕⊝
moderate
*Sepsis defined as micro-erythrocyte sedimentation rate > 5 mm, total leucocyte count < 5000, CRP > 6 mg/dL, platelet count < 100,000 or a positive blood culture within the first 48 hours.

Pulmonary hypoplasiaRR 0.22 (0.06 - 0.88)34 (one study)⊕⊕⊝⊝
low
Pulmonary hypoplasia was diagnosed according to strict clinical and radiological criteria, however, this study was small and blinding to group allocation was not described and so we downgraded this evidence from moderate to low. More evidence is needed.

Maternal puerperal sepsisRR 0.20 (0.05 - 0.84)60 (one study**)⊕⊕⊕⊝
moderate
**Defined as fever > 38° C and a positive high vaginal swab culture.


GRADE Working Group grades of evidence
High quality: further research is very unlikely to change our confidence in the estimate of effect.
Moderate quality: further research is likely to have an important impact on our confidence in the estimate of effect and may change the estimate.
Low quality: further research is very likely to have an important impact on our confidence in the estimate of effect and is likely to change the estimate.
Very low quality: we are very uncertain about the estimate.

CI: confidence interval; CRP: C-reactive protein; RR: risk ratio

 

Background

  1. Top of page
  2. Summary of findings    [Explanations]
  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. Differences between protocol and review
  18. Index terms
 

Description of the condition

Preterm premature rupture of membranes (PPROM) remains the single most identifiable cause of preterm labour and a major contributor to perinatal mortality and morbidity. Oligohydramnios (reduced amniotic fluid volume) following PPROM is associated with a higher risk of chorioamnionitis, neonatal fetal infection and cord compression (Keirse 1989; Vintzileos 1985). Umbilical cord compression may cause persistent variable fetal heart rate decelerations (Gabbe 1976). Oligohydramnios is also the most important predictor of perinatal mortality in very early PPROM and adequate residual amniotic fluid plays a critical role in determining the prevalence of pulmonary hypoplasia, which is a major cause of death in these babies (Vergani 1994; Vintzileos 1985). Abnormal neurological outcomes and postural deformities in the neonate may also occur as a consequence of PPROM (Locatelli 2000).

 

Description of the intervention

Saline fluid or Ringers lactate/Hartmans is infused transcervically through a catheter into the uterine cavity, or transabdominally, through a narrow gauge needle. Amnioinfusion was first described as a method of preventing or relieving umbilical cord compression during labour (Miyazaki 1983). The technique has since been used prophylactically in various conditions associated with oligohydramnios, including impaired intrauterine growth and PPROM. Amnioinfusion has been shown to prolong the latency period in second trimester PPROM (Locatelli 2000; Ogunyemi 2002; Turhan 2002), improve perinatal survival (Locatelli 2006; Ogunyemi 2002) and decrease rates of pulmonary hypoplasia (Locatelli 2000). Combined with antibiotics and without, it has been used to treat and to prevent infection following premature rupture of membranes (Goodlin 1981; Monahan 1995; Ogita 1988). In a Cochrane review on amnioinfusion for suspected or potential cord compression in labour at term, amnioinfusion improved short-term measures of neonatal outcome, reduced the use of caesarean section and reduced maternal puerperal sepsis (Hofmeyr 2012). A subcutaneously implanted amniotic fluid replacement port system has been developed for long-term amnioinfusion in women with preterm premature rupture of the membranes (Tchirikov 2010).

 

How the intervention might work

Restoring the amniotic fluid volume cushions the fetus, thereby preventing mechanical compression of the umbilical cord and reducing fetal distress. It may prevent fetal lung hypoplasia in PPROM by preventing mechanical compression of the fetal thorax and enabling normal amniotic fluid flow into the fetal lungs (Tranquilli 2005). This effect occurs mainly in the second trimester and is considered in a separate review (Van Teeffelen 2013). Likewise, by preventing mechanical compression of the fetus, amnioinfusion may prevent postural deformities. In addition, the infused fluid may prevent intrauterine infection, possibly by the anti-bacterial effect of saline, or a diluent effect. Improvements in fetal ductus venosus and umbilical artery flow have been demonstrated following amnioinfusion for PPROM (Hsu 2009).

 

Why it is important to do this review

Evidence from cohort studies suggests that replenishing the amniotic fluid volume in pregnancies complicated by PPROM is beneficial to mother and child. However, amnioinfusion is an invasive procedure and not without potential risks, thus a thorough evaluation of randomised controlled trials is required.

['Amnioinfusion for cord compression' (Hofmeyr 2012), 'Prophylactic versus therapeutic amnioinfusion' (Novikova 2012), and 'Amnioinfusion for meconium-stained liquor' (Hofmeyr 2014), are separate reviews.]

 

Objectives

  1. Top of page
  2. Summary of findings    [Explanations]
  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. Differences between protocol and review
  18. Index terms

To assess from the best available evidence the effects of amnioinfusion for preterm premature rupture of membranes on perinatal morbidity and mortality.

 

Methods

  1. Top of page
  2. Summary of findings    [Explanations]
  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. Differences between protocol and review
  18. Index terms
 

Criteria for considering studies for this review

 

Types of studies

Clinical trials comparing the effect of amnioinfusion for third trimester preterm premature rupture of the membranes before 37 weeks with a control group (no amnioinfusion); random allocation to treatment and control groups, with adequate allocation concealment; violations of allocated management and exclusions after allocation not sufficient to materially affect outcomes. Quasi-randomised (alternate allocation), cross-over and cluster trials were not considered eligible for inclusion.

 

Types of participants

Pregnant women with preterm premature rupture of membranes.

 

Types of interventions

Amnioinfusion compared with no amnioinfusion.

 

Types of outcome measures

 

Primary outcomes

  • Indicators of fetal condition, e.g. persistent variable decelerations, Apgar scores, cord arterial pH at birth.
  • Neonatal morbidity including infection, lung hypoplasia, abnormal neurological outcomes and postural deformities.
  • Perinatal mortality.

 

Secondary outcomes

  • Mode of delivery.
  • Indications for delivery.
  • Latency period from amnioinfusion to delivery.
  • Maternal morbidity, e.g. endometritis, postpartum temperature greater than 38°C.
  • Birthweight.
  • Admission to neonatal intensive or high care unit.

We considered outcomes separately for transcervical and transabdominal amnioinfusion.

The methods section of this review is based on a standard template used by the Cochrane Pregnancy and Childbirth Group.

 

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 (2 December 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. monthly 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 did not apply any language restrictions.

 

Data collection and analysis

No new studies have been included for this update (2014).

For methods used in the previous version of this review, please see Hofmeyr 2011.

For methods to be used in the next update, see Appendix 1.

 

Selection of studies

T Lawrie (TL), AC Eke (ACE) and GJ Hofmeyr (GJH) independently assessed for inclusion all potential studies. No studies were identified from the updated search. Two studies previously in ongoing were excluded (Roberts: AMIPROM; Vergani 2007). We resolved any disagreement through discussion. We evaluated trials under consideration for methodological quality and appropriateness for inclusion according to the prespecified selection criteria, without consideration of their results.

 

Results

  1. Top of page
  2. Summary of findings    [Explanations]
  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. Differences between protocol and review
  18. Index terms
 

Description of studies

In total, we have included five studies; three in the transcervical amnioinfusion comparison (Gonzalez 2001; Nageotte 1985; Puertas 2007) and two in the transabdominal comparison (Singla 2010; Tranquilli 2005). One included study contributed no data (Gonzalez 2001). See Characteristics of included studies. The gestational age range for recruitment to the transcervical trials was 26 to 36+ weeks and in the transabdominal trials, 24 to 34 weeks. Transcervical amnioinfusion was performed in a total of 72 women versus 75 controls (excluding unusable data from Gonzalez 2001) and transabdominal amnioinfusion was performed in 47 women versus 47 controls; thus participant numbers for this review are small.

 

Risk of bias in included studies

All included studies were randomised trials. See Figure 1 and Figure 2 for a summary of 'Risk of bias' assessments.

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

 

Allocation

Randomisation was by random number table in Puertas 2007 and was computer-generated in Tranquilli 2005 and Singla 2010; the method of randomisation and group allocation was not described in Nageotte 1985 and Gonzalez 2001. Allocation concealment was described in two trials (Puertas 2007; Tranquilli 2005).

 

Blinding

Partial blinding was described in two trials (Nageotte 1985; Puertas 2007).

 

Incomplete outcome data

Incomplete outcome data were noted in the randomised clinical trial by Gonzalez et al. This is because it is an abstract only publication, hence provided insufficient detail for assessment (Gonzalez 2001). Five post-randomisation exclusions: three for non-vertex presentation and two for fetal distress were noted in the randomised trial by Nageotte et al (Nageotte 1985). Otherwise, outcome data were complete for Puertas 2007, Singla 2010 and Tranquilli 2005.

 

Selective reporting

In the randomised clinical trial by Tranquilli et al, the authors did not report the mode of delivery, Apgar scores or cord arterial pH for the babies delivered (Tranquilli 2005). No selective reporting was found in the Puertas 2007 and Singla 2010 trials. There was insufficient information to assess selective reporting in Gonzalez 2001 and Nageotte 1985.

 

Other potential sources of bias

Another source of bias was noted in the randomised clinical trial by Puertas et al, where more carriers of group B streptococcal were noted in control group (14 women versus seven women) (Puertas 2007). Even though all these women with Group B streptococcal infection received prophylactic intrapartum antibiotics, the higher incidence of Group B Streptococcus in the control group was a source of bias for the trial. No other biases were reported for Singla 2010 and Tranquilli 2005. There was insufficient information to assess other sources of bias in Gonzalez 2001 and Nageotte 1985.

 

Effects of interventions

See:  Summary of findings for the main comparison

 

1. Transcervical amnioinfusion

Transcervical amnioinfusion improved fetal umbilical artery pH at delivery (mean difference (MD) 0.11; 95% confidence interval (CI) 0.08 to 0.14; one trial, 61 participants;  Analysis 1.6) and reduced persistent variable decelerations during labour (risk ratio (RR) 0.52; 95% CI 0.30 to 0.91; one trial, 86 participants;  Analysis 1.1). No significant differences in the rates of caesarean section, low Apgar scores, neonatal death or infectious morbidity were detected.

 

2. Transabdominal amnioinfusion

Transabdominal amnioinfusion was associated with a reduction in neonatal death (RR 0.30; 95% CI 0.14 to 0.66; two trials, 94 women;  Analysis 2.7), neonatal infection/sepsis (RR 0.26; 95% CI 0.11 to 0.61; one trial, 60 participants;  Analysis 2.3), and pulmonary hypoplasia (RR 0.22; 95% CI 0.06 to 0.88; one trial, 34 participants;  Analysis 2.3). Women in the amnioinfusion group were also less likely to deliver within seven days of membrane rupture (RR 0.18; 95% CI 0.05 to 0.70; one trial, 34 participants;  Analysis 2.4) and were less likely to experience puerperal sepsis (RR 0.20; 95% CI 0.05 to 0.84; one trial, 60 participants;  Analysis 2.9). There were no significant differences between groups regarding birthweight, gestational age at delivery, admission to neonatal intensive care and neurological sequelae. Fetal distress was diagnosed less frequently in the amnioinfusion group than the control group (RR 0.27; 95% CI 0.08 to 0.88; one trial, 60 participants;  Analysis 2.1), but in the absence of blinding this outcome is at risk of bias.

 

Discussion

  1. Top of page
  2. Summary of findings    [Explanations]
  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. Differences between protocol and review
  18. Index terms
 

Summary of main results

Transabdominal amnioinfusion following preterm premature rupture of the membranes (PPROM) resulted in better neonatal outcomes (decreased sepsis, infection and death) and decreased puerperal sepsis than conventional management. The data contributing to these outcomes were mainly from one trial (Singla 2010). Transcervical amnioinfusion was associated with improved fetal heart rate patterns and umbilical cord blood pH results, but improvements in substantive clinical outcomes were not statistically significant.

 

Overall completeness and applicability of evidence

These results are not conclusive due to the small numbers of trials and participants. In addition, the numbers are too small to detect rare potential adverse events. The lower threshold of gestational age at which amnioinfusion may be of benefit is not known.

 

Quality of the evidence

The evidence is of mainly moderate quality ( Summary of findings for the main comparison) and limitations can largely be attributed to the small size of studies and the lack of blinding to group allocation.

 

Agreements and disagreements with other studies or reviews

This evidence supports the positive findings of the non-randomised studies conducted to date.

 

Authors' conclusions

  1. Top of page
  2. Summary of findings    [Explanations]
  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. Differences between protocol and review
  18. Index terms

 

Implications for practice

There is currently insufficient evidence to guide clinical practice concerning the use of amnioinfusion for preterm premature rupture of the membranes.

 
Implications for research

Larger trials are needed to confirm and extend the findings of the trials reviewed here. Long-term follow-up of babies is desirable, especially with regard to neurological sequelae and development. Future trials and reviews may need to be stratified according to gestational age to determine whether there is a threshold for benefits and risks.

 

Acknowledgements

  1. Top of page
  2. Summary of findings    [Explanations]
  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. Differences between protocol and review
  18. Index terms

Sara Roden-Scott, Julieta Mattera and Nadia Bondarczuk for providing a translation for the Spanish trial report of Mino 1999.

 

Data and analyses

  1. Top of page
  2. Summary of findings    [Explanations]
  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. Differences between protocol and review
  18. Index terms
Download statistical data

 
Comparison 1. Transcervical amnioinfusion for preterm rupture of membranes

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

 1 Persistant variable decelerations186Risk Ratio (M-H, Fixed, 95% CI)0.52 [0.30, 0.91]

 2 Severe variable decelerations per hour in first stage161Mean Difference (IV, Fixed, 95% CI)-1.2 [-1.83, -0.57]

 3 Caesarean section2Risk Ratio (M-H, Random, 95% CI)Subtotals only

    3.1 Caesarean section overall
2147Risk Ratio (M-H, Random, 95% CI)0.65 [0.25, 1.73]

    3.2 Caesarean section for fetal distress
186Risk Ratio (M-H, Random, 95% CI)0.43 [0.12, 1.55]

 4 Forceps/vacuum assisted delivery1Risk Ratio (M-H, Fixed, 95% CI)Subtotals only

    4.1 Overall
186Risk Ratio (M-H, Fixed, 95% CI)1.2 [0.58, 2.48]

    4.2 For fetal distress
186Risk Ratio (M-H, Fixed, 95% CI)0.11 [0.01, 2.00]

 5 1 minute Apgar score < 4161Risk Ratio (M-H, Fixed, 95% CI)0.28 [0.03, 2.33]

 6 Umbilical arterial pH161Mean Difference (IV, Fixed, 95% CI)0.11 [0.08, 0.14]

 7 Umbilical pH ≤ 7.20186Risk Ratio (M-H, Fixed, 95% CI)0.25 [0.06, 1.11]

 8 Neonatal morbidity1Risk Ratio (M-H, Fixed, 95% CI)Subtotals only

    8.1 Overall
186Risk Ratio (M-H, Fixed, 95% CI)0.5 [0.19, 1.34]

 9 Neonatal death161Risk Ratio (M-H, Fixed, 95% CI)0.55 [0.05, 5.77]

 10 Maternal puerperal sepsis2147Risk Ratio (M-H, Fixed, 95% CI)0.36 [0.06, 2.18]

 
Comparison 2. Transabdominal amnioinfusion for preterm rupture of membranes

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

 1 Fetal distress160Risk Ratio (M-H, Fixed, 95% CI)0.27 [0.08, 0.88]

 2 Gestational age at delivery (weeks)294Mean Difference (IV, Random, 95% CI)-0.49 [-2.63, 1.65]

 3 Neonatal morbidity2Risk Ratio (M-H, Fixed, 95% CI)Subtotals only

    3.1 Neonatal sepsis/infection
160Risk Ratio (M-H, Fixed, 95% CI)0.26 [0.11, 0.61]

    3.2 Pulmonary hypoplasia
134Risk Ratio (M-H, Fixed, 95% CI)0.22 [0.06, 0.88]

    3.3 Abnormal neurological outcome
134Risk Ratio (M-H, Fixed, 95% CI)0.25 [0.03, 2.01]

 4 Delivery within 7 days134Risk Ratio (M-H, Fixed, 95% CI)0.18 [0.05, 0.70]

 5 Time to delivery (days)160Mean Difference (IV, Fixed, 95% CI)0.57 [-2.86, 4.00]

 6 Admission to neonatal intensive care unit134Risk Ratio (M-H, Fixed, 95% CI)1.0 [0.90, 1.12]

 7 Neonatal death294Risk Ratio (M-H, Fixed, 95% CI)0.3 [0.14, 0.66]

 8 Birthweight (grams)294Mean Difference (IV, Random, 95% CI)15.65 [-254.02, 285.32]

 9 Maternal puerperal sepsis160Risk Ratio (M-H, Fixed, 95% CI)0.2 [0.05, 0.84]

 

Appendices

  1. Top of page
  2. Summary of findings    [Explanations]
  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. Differences between protocol and review
  18. Index terms
 

Appendix 1. Methods to be used in the next update

 

Data collection and analysis

 

Selection of studies

Two review authors will independently assess for inclusion all the potential studies we identify as a result of the search strategy. We will resolve any disagreement through discussion or, if required, we will consult a third author.

 

Data extraction and management

We will design a form to extract data. For eligible studies, at least two review authors will extract the data using the agreed form. We will resolve discrepancies through discussion or, if required, we will consult a third person. We will enter data into Review Manager software (RevMan 2012) and check for accuracy.

When information regarding any of the above is unclear, we will attempt to contact authors of the original reports to provide further details.

 

Assessment of risk of bias in included studies

Two review authors will independently assess risk of bias for each study using the criteria outlined in the Cochrane Handbook for Systematic Reviews of Interventions (Higgins 2011). We will resolve any disagreement by discussion or by involving a third assessor.

 

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

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

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

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

We will assess 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 will describe for each included study, and for each outcome or class of outcomes, the completeness of data including attrition and exclusions from the analysis. We will state 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 is reported, or can be supplied by the trial authors, we will re-include missing data in the analyses which we undertake.

We will assess 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 will describe for each included study how we investigated the possibility of selective outcome reporting bias and what we found.

We will assess 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 will describe for each included study any important concerns we have about other possible sources of bias.

We will assess 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 will make explicit judgements about whether studies are at high risk of bias, according to the criteria given in the Cochrane Handbook (Higgins 2011). With reference to (1) to (6) above, we will assess the likely magnitude and direction of the bias and whether we consider it is likely to impact on the findings. We will explore the impact of the level of bias through undertaking sensitivity analyses - see 'Sensitivity analysis'.

 

Measures of treatment effect

 

Dichotomous data

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

 

Continuous data

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

 

Unit of analysis issues

 

Cluster-randomised trials

We will not consider cluster-randomised trials for inclusion.

 

Cross-over trials

We will not consider cross-over trials for inclusion.

 

Dealing with missing data

For included studies, we will note levels of attrition. We will explore the impact of including studies with high levels of missing data in the overall assessment of treatment effect by using sensitivity analysis.

For all outcomes, we will carry out analyses, as far as possible, on an intention-to-treat basis, i.e. we will attempt to include all participants randomised to each group in the analyses, and all participants will be analysed in the group to which they were allocated, regardless of whether or not they received the allocated intervention. The denominator for each outcome in each trial will be the number randomised minus any participants whose outcomes are known to be missing.

 

Assessment of heterogeneity

We will assess statistical heterogeneity in each meta-analysis using the Tau², I² and Chi² statistics. We will regard heterogeneity as substantial if an I² is greater than 30% and either the Tau² is greater than zero, or there is a low P value (< 0.10) in the Chi² test for heterogeneity.

 

Assessment of reporting biases

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. If asymmetry is suggested by a visual assessment, we will perform exploratory analyses to investigate it.

 

Data synthesis

We will carry out statistical analysis using the Review Manager software (RevMan 2012). We will use fixed-effect meta-analysis for combining data where it is reasonable to assume that studies are estimating the same underlying treatment effect: i.e. where trials are examining the same intervention, and the trials’ populations and methods are judged sufficiently similar. If there is clinical heterogeneity sufficient to expect that the underlying treatment effects differ between trials, or if substantial statistical heterogeneity is detected, we will use random-effects meta-analysis to produce an overall summary, if an average treatment effect across trials is considered clinically meaningful. The random-effects summary will be treated as the average range of possible treatment effects and we will discuss the clinical implications of treatment effects differing between trials. If the average treatment effect is not clinically meaningful, we will not combine trials.

If we use random-effects analyses, the results will be presented as the average treatment effect with 95% confidence intervals, and the estimates of Tau² and I².

 

Subgroup analysis and investigation of heterogeneity

If we identify substantial heterogeneity, we will investigate it using subgroup analyses and sensitivity analyses. We will consider whether an overall summary is meaningful, and if it is, use random-effects analysis to produce it.

We plan to carry out the following subgroup analyses.

  1. Effects of transabdominal versus transcervical amnioinfusion on complications of preterm premature rupture of the fetal membranes.
  2. Effects of transabdominal versus transcervical amnioinfusion at the various gestational ages in the third trimester.

The following outcomes will be used in subgroup analysis: persistent variable decelerations, Apgar scores, cord arterial pH at birth, neonatal morbidity including infection, lung hypoplasia, abnormal neurological outcomes and postural deformities, as well as perinatal mortality.

We will assess subgroup differences by interaction tests available within RevMan (RevMan 2012). We will report the results of subgroup analyses quoting the Chi² statistic and P value, and the interaction test I² value.

 

Sensitivity analysis

Sensitivity analyses will be performed for aspects of the review that might affect the results, for example, where there is risk of bias associated with the quality of some of the included trials. Sensitivity analysis will be carried out to explore the effects of fixed-effect or random-effects analyses for outcomes with statistical heterogeneity and the effects of any assumptions made.

 

What's new

  1. Top of page
  2. Summary of findings    [Explanations]
  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. Differences between protocol and review
  18. Index terms

Last assessed as up-to-date: 2 December 2013.


DateEventDescription

13 January 2014New citation required but conclusions have not changedTwo studies previously in ongoing have been excluded (Roberts: AMIPROM; Vergani 2007).

2 December 2013New search has been performedSearch updated. No new trials identified. Title changed from "Amnioinfusion for preterm premature rupture of membranes" to "Amnioinfusion for third trimester preterm premature rupture of membranes". See Differences between protocol and review for more details.



 

History

  1. Top of page
  2. Summary of findings    [Explanations]
  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. Differences between protocol and review
  18. Index terms

Protocol first published: Issue 1, 1998
Review first published: Issue 3, 2016


DateEventDescription

29 March 2011New citation required but conclusions have not changedNew authors helped to prepare this update.

5 January 2011New search has been performedSearch updated, one new trial identified (Singla 2010) and included. We have also included three trials previously awaiting classification (Gonzalez 2001; Puertas 2007; Tranquilli 2005).

We have also assessed the remaining trial reports from the previous search (previously in 'awaiting classification'), resulting in four excluded studies (De Santis 2003; Gowri 2004; Locatelli 2000; Mino 1999) and two ongoing studies (Roberts: AMIPROMa; Vergani 2007a).

2 July 2010AmendedContact details edited.

3 August 2009AmendedSearch updated. Nine reports added to Studies awaiting classification (De Santis 2003; Gonzalez 2001; Gowri 2004; Mino 1997a; Mino 1999; Roberts 2006; Puertas 2007; Tranquilli 2005; Vergani 2007a).

31 October 2008AmendedConverted to new review format.



 

Contributions of authors

  1. Top of page
  2. Summary of findings    [Explanations]
  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. Differences between protocol and review
  18. Index terms

GJ Hofmeyr prepared the review and maintains it. For the 2011 update, G Essilfie-Appiah assisted with the selection of studies and data extraction. T Lawrie assisted with study selection, data extraction and the text of the updated review. For the 2014 update, AC Eke assisted with the selection of studies, data extraction and the text of the updated review.

 

Declarations of interest

  1. Top of page
  2. Summary of findings    [Explanations]
  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. Differences between protocol and review
  18. Index terms

None known.

 

Sources of support

  1. Top of page
  2. Summary of findings    [Explanations]
  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. Differences between protocol and review
  18. Index terms
 

Internal sources

  • University of the Witwatersrand, South Africa.

 

External sources

  • South African Medical research Council, South Africa.
  • UNDP/UNFPA/WHO/World Bank (HRP), Switzerland.

 

Differences between protocol and review

  1. Top of page
  2. Summary of findings    [Explanations]
  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. Differences between protocol and review
  18. Index terms

In order to eliminate overlap between this review and a separate review (Van Teeffelen 2013), the title of this review has been changed from "Amnioinfusion for preterm premature rupture of membranes" to "Amnioinfusion for third trimester preterm premature rupture of membranes".

* Indicates the major publication for the study

References

References to studies included in this review

  1. Top of page
  2. AbstractRésumé
  3. Summary of findings
  4. Background
  5. Objectives
  6. Methods
  7. Results
  8. Discussion
  9. Authors' conclusions
  10. Acknowledgements
  11. Data and analyses
  12. Appendices
  13. What's new
  14. History
  15. Contributions of authors
  16. Declarations of interest
  17. Sources of support
  18. Differences between protocol and review
  19. Characteristics of studies
  20. References to studies included in this review
  21. References to studies excluded from this review
  22. Additional references
  23. References to other published versions of this review
Gonzalez 2001 {published data only}
  • Gonzalez R, Malde J, Carrillo MP, Sancho-Minano J, Garrote A, Munoz A, et al. The use of amnioinfusion in preterm deliveries. Preliminary results [abstract]. Journal of Perinatal Medicine 2001;29 Suppl 1(Pt 2):629.
Nageotte 1985 {published data only}
  • Nageotte MP, Freeman RK, Garite TJ, Dorchester W. Prophylactic intrapartum amnioinfusion in patients with preterm premature rupture of membranes. American Journal of Obstetrics and Gynecology 1985;153:557-62.
Puertas 2007 {published data only}
  • Puertas A, Tirado P, Perez I, Lopez MS, Montoya F, Canizares JM, et al. Transcervical intrapartum amnioinfusion for preterm premature rupture of the membranes. European Journal of Obstetrics & Gynecology and Reproductive Biology 2007;131(1):40-4.
Singla 2010 {published data only}
  • Singla A, Yadav P, Vaid NB, Suneja A, Faridi MMA. Transabdominal amnioinfusion in preterm premature rupture of membranes. International Journal of Gynecology & Obstetrics 2010;108:199-202.
Tranquilli 2005 {published data only}

References to studies excluded from this review

  1. Top of page
  2. AbstractRésumé
  3. Summary of findings
  4. Background
  5. Objectives
  6. Methods
  7. Results
  8. Discussion
  9. Authors' conclusions
  10. Acknowledgements
  11. Data and analyses
  12. Appendices
  13. What's new
  14. History
  15. Contributions of authors
  16. Declarations of interest
  17. Sources of support
  18. Differences between protocol and review
  19. Characteristics of studies
  20. References to studies included in this review
  21. References to studies excluded from this review
  22. Additional references
  23. References to other published versions of this review
De Santis 2003 {published data only}
  • De Santis M, Scavo M, Noia G, Masini L, Piersigilli F, Romagnoli C, et al. Transabdominal amnioinfusion treatment of severe oligohydramnios in preterm premature rupture of membranes at less than 26 gestational weeks. Fetal Diagnosis and Therapy 2003;18(6):412-7.
Gowri 2004 {published data only}
  • Gowri R, Soundaraghavan S. Evaluation of transabdominal amnioinfusion in the antepartum management of oligohydramnios complicating preterm pregnancies. Journal of Obstetrics and Gynaecology of India 2004;54(5):460-3.
Locatelli 2000 {published data only}
  • Locatelli A, Vergani P, Di Pirro G, Doria V, Biffi A, Ghidini A. Role of amnioinfusion in the management of premature rupture of membranes at < 26 weeks gestation. American Journal of Obstetrics and Gynecology 2000;183:878-82.
Mino 1999 {published data only}
  • Mino M, Puertas A, Carrillo M, Santiago J, Herruzo A, Miranda J. Influence of amnioinfusion on variable or prolonged decelarations: a randomised study. Acta Obstetricia et Gynecologica Scandinavica 1997;76:95.
  • Mino M, Puertas A, Herruzo AJ, Miranda JA. Amnioinfusion in labor induction of term pregnancies with premature rupture of the membranes and low amniotic fluid. International Journal of Gynecology & Obstetrics 1998;61:135-40.
  • Mino M, Puertas A, Miranda JA, Herruzo AJ. Amnioinfusion in term labor with low amniotic fluid due to rupture of membranes: a new indication. European Journal of Obstetrics & Gynecology and Reproductive Biology 1999;82:29-34.
  • Mino M, Puertas A, Mozas J, Carrillo Badillo MP, Rodríguez Oliver A, Miranda JA. A modification of the amniotic fluid index after amnioinfusion for infants with early rupture of membranes [Modificacion del indice de liquido amniotico tras amnioinfusion en gestantes con rotura prematura de membranas a termino]. Acta Ginecologica 1997;51(1):11-4.
  • Puertas A, Mino M, Carrillo M, Mozas J, Herruzo A, Miranda J. Influence of amnioinfusion on neonatal acid-base state: a randomized study. Acta Obstetricia et Gynecologica Scandinavica Supplement 1997;76:94.
Roberts: AMIPROM {unpublished data only}
  • Roberts D, Alfirevic Z, Bricker L, Beardsmore C, Paturi P, Taylor S, et al. Amnioinfusion in preterm premature rupture of membranes (AMIPROM study). Current Controlled Trials (www.controlled-trials.com/) (accessed 17 December 2013).
  • Roberts D, Beardsmore C, Shaw B, Martin W, Vause S, Bricker L, et al. AMIPROM: a pilot RCT on serial transabdominal amnioinfusion versus expectant management in very early PROM. Ultrasound in Obstetrics & Gynecology 2012;40(Suppl 1):80.
  • Roberts D, Vause S, Martin W, Green P, Walkinshaw S, Bricker L, et al. Amnioinfusion in very early preterm premature rupture of membranes - pregnancy, neonatal and maternal outcomes in the AMIPROM randomised controlled pilot study. Ultrasound in Obstetrics & Gynecology 2013 Nov 21 [Epub ahead of print].
  • Roberts D, Vause S, Martin W, Green P, Walkinshaw S, Bricker L, et al. Pregnancy outcomes in AMIPROM: a pilot RCT on serial transabdominal amnioinfusion versus expectant management in very early preterm prelabour rupture of membranes. BJOG: an international journal of obstetrics and gynaecology 2013;120(Suppl s1):10.
Vergani 2007 {published data only}
  • Vergani P, Deprest J, Strobelt N, Locatelli A. Proposal for open randomized trial comparing perinatal outcome following expectant management versus amnioinfusion in PPROM < 25 weeks with persistent oligohydramnios (amnioinfusion initiative). Ultrasound in Obstetrics and Gynecology 2007;30:541.

Additional references

  1. Top of page
  2. AbstractRésumé
  3. Summary of findings
  4. Background
  5. Objectives
  6. Methods
  7. Results
  8. Discussion
  9. Authors' conclusions
  10. Acknowledgements
  11. Data and analyses
  12. Appendices
  13. What's new
  14. History
  15. Contributions of authors
  16. Declarations of interest
  17. Sources of support
  18. Differences between protocol and review
  19. Characteristics of studies
  20. References to studies included in this review
  21. References to studies excluded from this review
  22. Additional references
  23. References to other published versions of this review
Gabbe 1976
  • Gabbe SG, Ettinger BB, Freeman RK, Martin CB. Umbilical cord compression associated with amniotomy: laboratory observations. American Journal of Obstetrics and Gynecology 1976;126(3):353-5.
Goodlin 1981
Higgins 2011
  • Higgins JPT, Green S, editors. Cochrane Handbook for Systematic Reviews of Interventions Version 5.1.0 [updated September 2011]. The Cochrane Collaboration, 2011. Available from www.cochrane-handbook.org.
Hofmeyr 2012
Hofmeyr 2014
Hsu 2009
  • Hsu TY, Hsu JJ, Fu HC, Ou CY, Tsai CC, Cheng BH, et al. The changes in Doppler indices of fetal ductus venosus and umbilical artery after amnioinfusion for women with preterm premature rupture of membranes before 26 weeks' gestation. Taiwan Journal of Obstetrics and Gynecology 2009;48(3):268-72.
Keirse 1989
  • Keirse MJNC, Ohlsson A, Treffers PE, Kanhai HHH. Prelabour rupture of the membranes preterm. In: Chalmers I, Enkin MW, Keirse MJNC editor(s). Effective Care in Pregnancy and Childbirth. Oxford: Oxford University Press, 1989:666-93.
Locatelli 2006
  • Locatelli A, Ghidini A, Verderio M, Andreani M, Strobelt N, Pezzullo J, et al. Predictors of perinatal survival in a cohort of pregnancies with severe oligohydramnios due to premature rupture of membranes at < 26 weeks managed with serial infusions. European Journal of Obstetrics & Gynecology and Reproductive Biology 2006;128(1-2):97-102.
Miyazaki 1983
Monahan 1995
Novikova 2012
Ogita 1988
  • Ogita S, Imanaka M, Matsumoto M, Oka T, Sugawa T. Transcervical amnioinfusion of antibiotics: a basic study for managing premature rupture of membranes. American Journal of Obstetrics and Gynecology 1988;158(1):23-7.
Ogunyemi 2002
  • Ogunyemi D, Thompson W. A case controlled study of serial transabdominal amnioinfusions in the management of second trimester oligohydramnios due to premature rupture of membranes. European Journal of Obstetrics & Gynecology and Reproductive Biology 2002;102(2):167-72.
RevMan 2012
  • The Nordic Cochrane Centre, The Cochrane Collaboration. Review Manager (RevMan). 5.2. Copenhagen: The Nordic Cochrane Centre, The Cochrane Collaboration, 2012.
Tchirikov 2010
  • Tchirikov M, Steetskamp J, Hohmann M, Koelbl H. Long-term amnioinfusion through a subcutaneously implanted amniotic fluid replacement port system for treatment of PPROM in humans. European Journal of Obstetrics & Gynecology and Reproductive Biology 2010;152:30-3.
Turhan 2002
  • Turhan NO, Atacan N. Antepartum prophylactic transabdominal amnioinfusion in preterm pregnancies complicated by oligohydramnios. International Journal of Gynecology & Obstetrics 2002;76(1):15-21.
Van Teeffelen 2013
  • Van Teeffelen S, Pajkrt E, Willekes C, Van Kuijk SMJ, Mol BWJ. Transabdominal amnioinfusion for improving fetal outcomes after oligohydramnios secondary to preterm prelabour rupture of membranes before 26 weeks. Cochrane Database of Systematic Reviews 2013, Issue 8. [DOI: 10.1002/14651858.CD009952.pub2]
Vergani 1994
  • Vergani P, Ghidini A, Locatelli A, Cavallone M, Ciarla I, Cappellini A, et al. Risk factors of pulmonary hypoplasia in second trimester premature rupture of membranes. American Journal of Obstetrics and Gynecology 1994;170:1359-64.
Vergani 1997
  • Vergani P, Locatelli A, Strobelt N, Mariani S, Cavallone M, Arosio P, et al. Amnioinfusion for prevention of pulmonary hypoplasia in second-trimester rupture of membranes. American Journal of Perinatology 1997;14(6):325-9.
Vintzileos 1985
  • Vintzileos AM, Campbell WA, Nochimson DJ, Weinbaum PJ. Degree of oligohydramnios and pregnancy outcome in patients with premature rupture of membranes. Obstetrics & Gynecology 1985;66(2):162-7.

References to other published versions of this review

  1. Top of page
  2. AbstractRésumé
  3. Summary of findings
  4. Background
  5. Objectives
  6. Methods
  7. Results
  8. Discussion
  9. Authors' conclusions
  10. Acknowledgements
  11. Data and analyses
  12. Appendices
  13. What's new
  14. History
  15. Contributions of authors
  16. Declarations of interest
  17. Sources of support
  18. Differences between protocol and review
  19. Characteristics of studies
  20. References to studies included in this review
  21. References to studies excluded from this review
  22. Additional references
  23. References to other published versions of this review
Hofmeyr 1995
  • Hofmeyr GJ. Amnioinfusion for preterm prelabour rupture of membranes [revised 22 April 1993]. In: Enkin MW, Keirse MJNC, Renfrew MJ, Neilson JP, Crowther C (eds.) Pregnancy and Childbirth Module. In: The Cochrane Database of Systematic Reviews [database on disk and CDROM]. The Cochrane Collaboration; Issue 2, Oxford: Update Software; 1995.
Hofmeyr 1998b
Hofmeyr 2011