Oxytocin Versus Dinoprostone Vaginal Insert for Induction of Labor After Previous Cesarean Delivery: A Retrospective Comparative Study

Abstract

Several studies have shown increased morbidity among newborn infants delivered during nighttime compared with those born in the daytime. However, others have reported comparable neonatal outcomes for these 2 periods. The risk of a nighttime delivery remains unclear.To identify possible high-risk periods for delivery of infants, this retrospective study compared neonatal morbidity and other birth outcomes between night and the rest of day and within 2 periods in the internal night. Between 2003 and 2007, maternal and neonatal data were obtained for spontaneous deliveries of singleton term (Ն37 weeks) pregnancies in labor with cephalic presentation. The main periods examined were the night shift between 11.00 PM and 7.00 AM (period 1) and the rest of day between 7.00 AM and 11.00 PM (period 2). The night shift was then subdivided into 2 equal time frames: between 11.00 PM and 3.00 AM (period 1a) and between 3.00 AM and 7.00 AM (period 1b). Factors analyzed in all periods were demographic features, obstetric characteristics, and neonatal outcomes.Of the 3055 cases meeting inclusion criteria, 28.5% were delivered during the night shift (period 1) and 71.5% during the rest of day (period 2). During the night shift, 51.3% of infants were delivered between 11.00 PM and 3.00 AM (period 1a) and 48.7% were born between 3.00 AM and 7.00 AM (period 1b). No differences were found between periods 1 and 2 for all examined demographic features, obstetric characteristics, and neonatal outcomes. In the night shift, rates of emergent cesarean and instrumental delivery were significantly increased during period 1a (13.2% and 10.1%, respectively) compared with period 1b (4.0% and 6.4%, respectively). Moreover, the incidence of NICU (neonatal intensive care unit) admission (neonatal morbidity indicator) was significantly higher for period 1a compared with period 1b (2.7% vs. 0.5%).These findings demonstrate comparable neonatal morbidity between infants born during night shift and rest of day. However, analysis of the internal night shows higher rates of operative and instrumental delivery as well as NICU admission for infants delivered between 11.00 PM and 3.00 AM.