NIHR Signal Induction of labour within 24 hours, if waters break at 37 weeks of pregnancy, can reduce womb infection

Published on 23 May 2017

Inducing labour may halve the risk of infection in the womb when waters break from 37 weeks. The procedure was started within 24 hours and was compared to waiting for labour to start on its own.

Waters breaking at full term without the onset of labour is called pre-labour rupture of membranes. This can increase risks of maternal and neonatal infection and the need for caesarean section. As most women deliver spontaneously within a day, NICE recommend that women are offered an informed choice of either induction 24 hours after premature rupture of membranes or to watch and wait.

This updated Cochrane review included new evidence and suggests that induction before 24 hours may reduce infections without increasing caesarean sections, but there remains some uncertainty. This is due to low study quality, lack of longer term outcomes, and too few participants in trials to compare the numbers of any rare serious events.

These findings may help inform shared decisions about induction by providing more information to help women understand the risks. 

Induction of labour within 24 hours, if waters break at 37 weeks of pregnancy, can reduce womb infection

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Why was this study needed?

Premature rupture of membranes (PROM) at full term (37 weeks or more) occurs in 8% of pregnancies. Spontaneous onset of labour within 24 hours occurs in approximately 95% of cases. Labour can be delayed for up to seven days if it does not start within 24 hours.

The risk of maternal or neonatal infection and the need for caesarean section are increased by PROM. Untreated infections can lead to complications with reproductive organs, problems with fertility and general health.

PROM at term is managed by either by inducing labour quickly (usually the next morning i.e. under 24 hours) or expectant management which involves waiting for labour to begin and induction of labour if it does not occur in a specific period or there are other reasons to intervene.

It is not clear if waiting for birth to occur spontaneously or intervening to induce labour within the first 24 hours has better outcomes for the mother and baby, everything else being equal.

This updated Cochrane review included eight new trials and aimed to compare the effects of each management strategy.

What did this study do?

This systematic review and meta-analysis included 23 randomised controlled trials including 8,615 women at full term that had PROM. Eleven trials were conducted in Europe or US/Canada.

Trials were included if they compared the effects of immediate induction intervention or intervention within 24 hours to no planned intervention within 24 hours (expectant management).

The main outcomes were whether either option was better at reducing the risk of maternal infection in the lining of the uterus (endometritis) and/or the fetal membranes (chorioamnionitis) or the need for caesarean section. Researchers also looked for stillbirths or complications for the baby recorded in the trials.

For some outcomes, the quality of the evidence was downgraded to low due to a high risk of bias and large differences between the studies. However, the maternal infection and caesarean section outcomes are objective so we are moderately confident in these results.

What did it find?

  • Low quality evidence from eight trials (6,864 women) found women who had an intervention to induce labour within 24 hours of PROM had a reduced risk of chorioamnionitis and/or endometritis (54 per 1,000) compared to women who had expectant management (110 per 1,000); risk ratio (RR) 0.49, 95% confidence interval (CI) 0.33 to 0.72. Subgroup analyses showed women with a planned induction intervention had a reduced risk of chorioamnionitis (RR 0.55, 95% CI 0.37 to 0.82). There was no difference for endometritis but this was based on one small trial of 86 women from 1989.
  • Low quality evidence from 23 trials (8,576 women) found no significant difference in the risk of caesarean section between women with planned interventions to induce labour (126 per 1,000) compared to expectant management (150 per 1,000); RR 0.84, 95% CI 0.69 to 1.04.
  • Very low quality evidence from three trials reported no serious maternal outcomes or deaths and therefore found no difference between the intervening to induce labour and expectant management groups. However, stillbirths and maternal deaths are rare outcomes in the UK.
  • Low quality evidence from 16 trials (7,314 infants) found women who had an intervention to induce labour had less likelihood of their babies having definite or probable sepsis (30 per 1,000) compared to women who had expectant management (41 per 1,000); RR 0.73, 95% CI 0.58 to 0.92.
  • Moderate evidence from eight trials (6,392 infants) found no significant difference in stillbirth or neonatal death for women with a planned intervention (1 per 1,000) compared to expectant management (2 per 1,000); RR 0.47, 95% CI 0.13 to 1.66.

What does current guidance say on this issue?

NICE’s 2008 guidance on induction of labour recommends that women with PROM at or over 37 weeks be offered a choice of induction of labour with vaginal prostaglandin or expectant management. It states that induction of labour is appropriate approximately 24 hours after the rupture of the membranes occurs.

Parts of this 2008 guideline are currently being updated, including the recommended methods for induction of labour. The recommendations stated above on information and advice for women being offered induction of labour are not under review.

What are the implications?

Given the remaining uncertainties highlighted in this review and the fact that most women with PROM will give birth anyway within 24 hour, implications are tentative. No clear recommendations are possible from this review, on which of the different induction techniques including vaginal or oral prostaglandins, intravenous oxytocin, acupuncture and homeopathy are best.

However, for some outcomes there are some risk estimates here that could be helpful for midwives, obstetricians and women seeking to understand the relative risks of these shared decisions. These decisions, of course, cannot be avoided.

Citation and Funding

Middleton P, Shepherd E, Flenady V, et al. Planned early birth versus expectant management (waiting) for prelabour rupture of membranes at term (37 weeks or more). Cochrane Database Syst Rev. 2017(1):CD005302.

This project was funded by the National Institute for Health Research Cochrane Programme Grant project (project number 13/89/05), the NHS Programme for Research & Development, the Australian Research for Health of Women and Babies and the National Health and Medical Research Council in Australia.

Bibliography

NICE. Inducing labour. CG70. London: National Institute for Health and Care Excellence; 2008.

Why was this study needed?

Premature rupture of membranes (PROM) at full term (37 weeks or more) occurs in 8% of pregnancies. Spontaneous onset of labour within 24 hours occurs in approximately 95% of cases. Labour can be delayed for up to seven days if it does not start within 24 hours.

The risk of maternal or neonatal infection and the need for caesarean section are increased by PROM. Untreated infections can lead to complications with reproductive organs, problems with fertility and general health.

PROM at term is managed by either by inducing labour quickly (usually the next morning i.e. under 24 hours) or expectant management which involves waiting for labour to begin and induction of labour if it does not occur in a specific period or there are other reasons to intervene.

It is not clear if waiting for birth to occur spontaneously or intervening to induce labour within the first 24 hours has better outcomes for the mother and baby, everything else being equal.

This updated Cochrane review included eight new trials and aimed to compare the effects of each management strategy.

What did this study do?

This systematic review and meta-analysis included 23 randomised controlled trials including 8,615 women at full term that had PROM. Eleven trials were conducted in Europe or US/Canada.

Trials were included if they compared the effects of immediate induction intervention or intervention within 24 hours to no planned intervention within 24 hours (expectant management).

The main outcomes were whether either option was better at reducing the risk of maternal infection in the lining of the uterus (endometritis) and/or the fetal membranes (chorioamnionitis) or the need for caesarean section. Researchers also looked for stillbirths or complications for the baby recorded in the trials.

For some outcomes, the quality of the evidence was downgraded to low due to a high risk of bias and large differences between the studies. However, the maternal infection and caesarean section outcomes are objective so we are moderately confident in these results.

What did it find?

  • Low quality evidence from eight trials (6,864 women) found women who had an intervention to induce labour within 24 hours of PROM had a reduced risk of chorioamnionitis and/or endometritis (54 per 1,000) compared to women who had expectant management (110 per 1,000); risk ratio (RR) 0.49, 95% confidence interval (CI) 0.33 to 0.72. Subgroup analyses showed women with a planned induction intervention had a reduced risk of chorioamnionitis (RR 0.55, 95% CI 0.37 to 0.82). There was no difference for endometritis but this was based on one small trial of 86 women from 1989.
  • Low quality evidence from 23 trials (8,576 women) found no significant difference in the risk of caesarean section between women with planned interventions to induce labour (126 per 1,000) compared to expectant management (150 per 1,000); RR 0.84, 95% CI 0.69 to 1.04.
  • Very low quality evidence from three trials reported no serious maternal outcomes or deaths and therefore found no difference between the intervening to induce labour and expectant management groups. However, stillbirths and maternal deaths are rare outcomes in the UK.
  • Low quality evidence from 16 trials (7,314 infants) found women who had an intervention to induce labour had less likelihood of their babies having definite or probable sepsis (30 per 1,000) compared to women who had expectant management (41 per 1,000); RR 0.73, 95% CI 0.58 to 0.92.
  • Moderate evidence from eight trials (6,392 infants) found no significant difference in stillbirth or neonatal death for women with a planned intervention (1 per 1,000) compared to expectant management (2 per 1,000); RR 0.47, 95% CI 0.13 to 1.66.

What does current guidance say on this issue?

NICE’s 2008 guidance on induction of labour recommends that women with PROM at or over 37 weeks be offered a choice of induction of labour with vaginal prostaglandin or expectant management. It states that induction of labour is appropriate approximately 24 hours after the rupture of the membranes occurs.

Parts of this 2008 guideline are currently being updated, including the recommended methods for induction of labour. The recommendations stated above on information and advice for women being offered induction of labour are not under review.

What are the implications?

Given the remaining uncertainties highlighted in this review and the fact that most women with PROM will give birth anyway within 24 hour, implications are tentative. No clear recommendations are possible from this review, on which of the different induction techniques including vaginal or oral prostaglandins, intravenous oxytocin, acupuncture and homeopathy are best.

However, for some outcomes there are some risk estimates here that could be helpful for midwives, obstetricians and women seeking to understand the relative risks of these shared decisions. These decisions, of course, cannot be avoided.

Citation and Funding

Middleton P, Shepherd E, Flenady V, et al. Planned early birth versus expectant management (waiting) for prelabour rupture of membranes at term (37 weeks or more). Cochrane Database Syst Rev. 2017(1):CD005302.

This project was funded by the National Institute for Health Research Cochrane Programme Grant project (project number 13/89/05), the NHS Programme for Research & Development, the Australian Research for Health of Women and Babies and the National Health and Medical Research Council in Australia.

Bibliography

NICE. Inducing labour. CG70. London: National Institute for Health and Care Excellence; 2008.

Planned early birth versus expectant management (waiting) for prelabour rupture of membranes at term (37 weeks or more)

Published on 5 January 2017

Middleton, P.,Shepherd, E.,Flenady, V.,McBain, R. D.,Crowther, C. A.

Cochrane Database Syst Rev Volume 1 , 2017

BACKGROUND: Prelabour rupture of membranes (PROM) at term is managed expectantly or by planned early birth. It is not clear if waiting for birth to occur spontaneously is better than intervening, e.g. by inducing labour. OBJECTIVES: The objective of this review is to assess the effects of planned early birth (immediate intervention or intervention within 24 hours) when compared with expectant management (no planned intervention within 24 hours) for women with term PROM on maternal, fetal and neonatal outcomes. SEARCH METHODS: We searched Cochrane Pregnancy and Childbirth's Trials Register (9 September 2016) and reference lists of retrieved studies. SELECTION CRITERIA: Randomised or quasi-randomised controlled trials of planned early birth compared with expectant management (either in hospital or at home) in women with PROM at 37 weeks' gestation or later. DATA COLLECTION AND ANALYSIS: Two review authors independently assessed trials for inclusion, extracted the data, and assessed risk of bias of the included studies. Data were checked for accuracy. MAIN RESULTS: Twenty-three trials involving 8615 women and their babies were included in the update of this review. Ten trials assessed intravenous oxytocin; 12 trials assessed prostaglandins (six trials in the form of vaginal prostaglandin E2 and six as oral, sublingual or vaginal misoprostol); and one trial each assessed Caulophyllum and acupuncture. Overall, three trials were judged to be at low risk of bias, while the other 20 were at unclear or high risk of bias.Primary outcomes: women who had planned early birth were at a reduced risk of maternal infectious morbidity (chorioamnionitis and/or endometritis) than women who had expectant management following term prelabour rupture of membranes (average risk ratio (RR) 0.49; 95% confidence interval (CI) 0.33 to 0.72; eight trials, 6864 women; Tau(2) = 0.19; I(2) = 72%; low-quality evidence), and their neonates were less likely to have definite or probable early-onset neonatal sepsis (RR 0.73; 95% CI 0.58 to 0.92; 16 trials, 7314 infants;low-quality evidence). No clear differences between the planned early birth and expectant management groups were seen for the risk of caesarean section (average RR 0.84; 95% CI 0.69 to 1.04; 23 trials, 8576 women; Tau(2) = 0.10; I(2) = 55%; low-quality evidence); serious maternal morbidity or mortality (no events; three trials; 425 women; very low-quality evidence); definite early-onset neonatal sepsis (RR 0.57; 95% CI 0.24 to 1.33; six trials, 1303 infants; very low-quality evidence); or perinatal mortality (RR 0.47; 95% CI 0.13 to 1.66; eight trials, 6392 infants; moderate-quality evidence). SECONDARY OUTCOMES: women who had a planned early birth were at a reduced risk of chorioamnionitis (average RR 0.55; 95% CI 0.37 to 0.82; eight trials, 6874 women; Tau(2) = 0.19; I(2) = 73%), and postpartum septicaemia (RR 0.26; 95% CI 0.07 to 0.96; three trials, 263 women), and their neonates were less likely to receive antibiotics (average RR 0.61; 95% CI 0.44 to 0.84; 10 trials, 6427 infants; Tau(2) = 0.06; I(2) = 32%). Women in the planned early birth group were more likely to have their labour induced (average RR 3.41; 95% CI 2.87 to 4.06; 12 trials, 6945 women; Tau(2) = 0.05; I(2) = 71%), had a shorter time from rupture of membranes to birth (mean difference (MD) -10.10 hours; 95% CI -12.15 to -8.06; nine trials, 1484 women; Tau(2) = 5.81; I(2) = 60%), and their neonates had lower birthweights (MD -79.25 g; 95% CI -124.96 to -33.55; five trials, 1043 infants). Women who had a planned early birth had a shorter length of hospitalisation (MD -0.79 days; 95% CI -1.20 to -0.38; two trials, 748 women; Tau(2) = 0.05; I(2) = 59%), and their neonates were less likely to be admitted to the neonatal special or intensive care unit (RR 0.75; 95% CI 0.66 to 0.85; eight trials, 6179 infants), and had a shorter duration of hospital (-11.00 hours; 95% CI -21.96 to -0.04; one trial, 182 infants) or special or intensive care unit stay (RR 0.72; 95% CI 0.61 to 0.85; four trials, 5691 infants). Women in the planned early birth group had more positive experiences compared with women in the expectant management group.No clear differences between groups were observed for endometritis; postpartum pyrexia; postpartum antibiotic usage; caesarean for fetal distress; operative vaginal birth; uterine rupture; epidural analgesia; postpartum haemorrhage; adverse effects; cord prolapse; stillbirth; neonatal mortality; pneumonia; Apgar score less than seven at five minutes; use of mechanical ventilation; or abnormality on cerebral ultrasound (no events).None of the trials reported on breastfeeding; postnatal depression; gestational age at birth; meningitis; respiratory distress syndrome; necrotising enterocolitis; neonatal encephalopathy; or disability at childhood follow-up.In subgroup analyses, there were no clear patterns of differential effects for method of induction, parity, use of maternal antibiotic prophylaxis, or digital vaginal examination. Results of the sensitivity analyses based on trial quality were consistent with those of the main analysis, except for definite or probable early-onset neonatal sepsis where no clear difference was observed. AUTHORS' CONCLUSIONS: There is low quality evidence to suggest that planned early birth (with induction methods such as oxytocin or prostaglandins) reduces the risk of maternal infectious morbidity compared with expectant management for PROM at 37 weeks' gestation or later, without an apparent increased risk of caesarean section. Evidence was mainly downgraded due to the majority of studies contributing data having some serious design limitations, and for most outcomes estimates were imprecise.Although the 23 included trials in this review involved a large number of women and babies, the quality of the trials and evidence was not high overall, and there was limited reporting for a number of important outcomes. Thus further evidence assessing the benefits or harms of planned early birth compared with expectant management, considering maternal, fetal, neonatal and longer-term childhood outcomes, and the use of health services, would be valuable. Any future trials should be adequately designed and powered to evaluate the effects on short- and long-term outcomes. Standardisation of outcomes and their definitions, including for the assessment of maternal and neonatal infection, would be beneficial.

Expert commentary

When to deliver following membrane rupture at term poses a significant clinical conundrum. Previous data suggested speeding up labour at the time of rupture reduced maternal infection without increasing caesarean section rates. The controversy continues as although early induction reduced maternal infectious morbidity and early neonatal sepsis with no differences in caesarean section rates, long term outcomes for the infant were not considered and included studies varied significantly with heterogeneous patient groups, study protocols and outcome definitions. Women should therefore have an active role in the decision-making process as intervention does not necessarily confer benefit.

Andrew Shennan, Professor of Obstetrics, King's College London & Dr Lisa Story, Tommy's Clinical Postdoctoral Research Fellow