[Premature rupture of membranes≥37 weeks of gestation: Predictive factors for labour onset within 24hours].

OBJECTIVES: To identify predictive criteria for a positive expectation in the context of rupture of membranes after 37 WG.

METHODS: Single-center retrospective study including ROM≥37 WG. The primary outcome was labour onset within 24hours. We compared predictive factors for occurrence of spontaneous labour and described obstetrical and neonatal outcomes according to initial Bishop score<6 or ≥6.

RESULTS: From January 2013 to December 2014, 520 patients were included. The predictive factors in case of unfavorable cervix were clinical leakage (P<0.001) and a cervical dilatation≥2cm (P<0.001) according to multivariate analysis. When the expectancy failed, there was a higher rate of cesarean section (24.3% vs. 9.6% P<0.001) but no more proven maternal-fetal infection. In case of Bishop≥6, we identified no predictive factor for labour onset but Apgar<7 at 5minutes (18.7% vs. 3.2% P=0.01) and admission to neonatal unit (18.8% vs. 3.2% P=0.04) were more frequent without majoration of maternal-fetal infection.

CONCLUSION: The favorable expectation was the outcome for 70.8% of ROM at term. Clinical leakage and dilated cervix appeared as the main predictors in case of Bishop<6. Majoration of low Apgar score and admission to neonatal unit could be increased when no labour onset occurred despite Bishop≥6.