90: Oral misoprostol vs vaginal dinoprostone for labor induction in nulliparous women at term

between 34 0 and 36 6 weeks of gestation Giuliana Simonazzi, Alessandra Curti, Elisa Moro, Andrea Pedrazzi, Tiziana Martina, Antonio Farina, Nicola Rizzo St. Orsola Malpighi Hospital, University of Bologna, Department of Obstetrics & Gynecology, Bologna, Italy OBJECTIVE: To assess the impact of mode of delivery on respiratory morbidity among late-preterm neonates. STUDY DESIGN: Singleton pregnancies complicated by premature rupture of membranes (PROM) between 34 0 and 36 6 weeks were studied retrospectively. Pregnancies with corticosteroid administration after 34 6 weeks were excluded. Patients were divided into cesarean section (CS) and vaginal delivery groups, matched 1:3 for gestational age. The primary outcome was the rate of respiratory distress syndrome (RDS). Logistic regression was performed to assess the risk of RDS within groups. RESULTS: Between 2005 and 2012, 360 patients delivered between 34 and 36 weeks after premature rupture of membranes at St. OrsolaMalpighi Hospital, Bologna (Italy). In 90 cases elective caesarean section was performed for previous CS (n 50), breech presentation (n 31) or maternal medical indications (n 9). No difference was found for antenatal betamethasone within groups. The overall RDS rate was 15%, while it was 30% and 10% in case of CS and vaginal delivery, respectively (p-value 0.0001). CS seems to be a risk factor for RDS (OR 4.2, p-value 0,0001), as does earlier gestational age at delivery (OR 0.9, p-value 0,0001). Table 1 shows the median risks of RDS in the study population according to the logistic regression model. CONCLUSION: After preterm PROM, CS is associated with a higher risk of neonatal RDS. This is more evident with increasing gestational age, when respiratory morbidity is thought to be less frequent.