Differences in neonatal morbidity depending on induction of labour after premature rupture of membranes

Over a period of about six months each, deliveries after premature rupture of membranes (FROM) and a confirmed gestational age of > 32 weeks were subjected to either of the following regimes: During the first 6 months induction was started 48 hours after FROM in the absence of spontaneous labour (Group 1). During the following 6 months labour was induced 12 hours after FROM in case of lacking labour-dependent cervical dilatation (Group 2). Progress of delivery and neonatal morbidity were analysed in both groups. 7.6% of the deliveries had to be induced in Group 1 compared with 25.7% in Group 2. No significant difference in the delivery rate after 48 hours and in the operative delivery rate could be observed (88.9% vs. 94.6% and 28.5% vs. 30.1%). Comparing both subgroups, which underwent induction, revealed an increased operative delivery rate in Group 2 (42% vs. 33%). The period of labour in this group was prolonged (15 hours vs 9 hours). Caesarean section because of an amnionic infection syndrome and transfer to the neonatal care unit were not found to be different in groups 1 and 2 as well as in the corresponding subgroups. Severe infections such as pneumonia or amnionic infection syndrome were observed in 3.8% (Group 1) and in 5.7% (Group 2). 7.4% of the newborn, delivered after induction of labour 12 hours following FROM, developed these infections, whereas no case arose when labour was induced after 48 hours. These data suggest no benefit for newborn delivered after induction of labour 12 hours following FROM, compared to newborn delivered after an expectant labour by induction after 48 hours.