Induction within or after 12 hours of ≥36 weeks' prelabor rupture of membranes: a systematic review and meta-analysis.

Objective: This study aimed to evaluate the incidence of chorioamnionitis in women with singleton gestations with ≥36 weeks' prelabor rupture of membranes induced with oxytocin within or after 12 hours of prelabor rupture of membranes.

Data Sources: The search was conducted using MEDLINE, Web of Sciences, Scopus, ClinicalTrial.gov, OVID, and Cochrane Library as electronic databases from their inception to May 2020.

Study Eligibility Criteria: Randomized controlled trials of women with singleton cephalic gestations and prelabor rupture of membranes at ≥36 weeks comparing induction of labor with oxytocin either ≤12 hours after prelabor rupture of membranes or >12 hours after prelabor rupture of membranes (expectant management group).

Study Appraisal And Synthesis Methods: The risk of bias in each included study was assessed using the criteria outlined in the Cochrane Handbook for Systematic Reviews of Interventions. All analyses were done using an intention-to-treat approach, evaluating women according to the treatment group to which they were randomly allocated in the original trials. The primary outcome was the incidence of chorioamnionitis.

Results: After exclusions, 9 randomized controlled trials including 3759 women were analyzed. Women with singleton cephalic gestations and prelabor rupture of membranes at ≥36 weeks who have induction of labor ≤12 hours after prelabor rupture of membranes have shorter time between prelabor rupture of membranes and delivery (-12.68 hours; 95% confidence interval, -16.15 to -9.21) and higher chance of delivering within 24 hours of prelabor rupture of membranes (91% vs 46%; relative risk, 1.93; 95% confidence interval, 1.59-2.35). Cesarean and operative vaginal deliveries were not significantly different between the groups. Induction of labor ≤12 hours after prelabor rupture of membranes was also associated with significantly fewer incidences of chorioamnionitis (5.3% vs 9.9%; relative risk, 0.62; 95% confidence interval, 0.40-0.97), endometritis (2.4% vs 4.2%; relative risk, 0.59; 95% confidence interval, 0.40-0.87), neonatal sepsis (6.1% vs 11.8%; relative risk, 0.46; 95% confidence interval, 0.27-0.79), and admission to neonatal intensive care unit (6.4% vs 12.0%; relative risk, 0.54; 95% confidence interval, 0.43-0.69) compared with women managed expectantly, usually at >24 hours. The subgroup analysis of 3323 women with induction of labor at ≤6 hours showed similar results, including similar significant reductions in chorioamnionitis, endometritis, neonatal sepsis, and admission to neonatal intensive care unit.

Conclusion: Women with symptoms of prelabor rupture of membranes at ≥36 weeks should be evaluated promptly, and if prelabor rupture of membranes is confirmed, they should have induction of labor within 12 hours and perhaps even within 6 hours since the first symptom of prelabor rupture of membranes. This management is associated with significantly less morbidity, especially in terms of infections, for both the mother and the baby, with no evidence of any harm.