The impact of time of delivery on gestations complicated by preterm premature rupture of membranes: daytime versus nighttime

Background: Perinatal death, in particular intrapartum stillbirth and short-term neonatal death, as well as neonatal short-term and long-term morbidity have been associated with the time of day that the birth occurs. Indeed, evening and nighttime deliveries were associated with an increased risk of an adverse perinatal outcome when compared to similar daytime deliveries. Impact of shift change, as well as time of day delivery have been extensively studied in the context of maternal and neonatal complications of cesarean delivery, however, no studies were previously performed on timing of delivery and its effect on the outcome of pregnancies complicated by preterm premature rupture of membranes. Objective: Our objective was to compare obstetric, neonatal as well as long-term outcomes between women delivered in the daytime versus nighttime, in singleton gestations whose pregnancies were complicated by preterm premature rupture of membranes. Study design: This was a secondary analysis of a trial of the Eunice Kennedy Shriver National Institute of Child Health and Human Development Maternal-Fetal Medicine Units Network “A Randomized Clinical Trial of the Beneficial Effects of Antenatal Magnesium Sulfate for the Prevention of Cerebral Palsy.” For this analysis, the time of delivery was divided into the daytime, from 07:01 to 19:00, and the nighttime, from 19:01 to 07:00. Epidemiological, obstetric characteristics as well as neonatal and long-term outcomes were compared between deliveries occurring during the daytime versus the nighttime periods. Inclusion criteria consisted of singleton gestations diagnosed with preterm premature rupture of membranes (PPROM). Multifetal gestations and pregnancies with preterm labor without preterm premature rupture of membranes were excluded. Results: A total of 1752 patients met inclusion criteria, 881 delivering during the daytime, while 871 during the nighttime. There were no differences in demographic maternal variables. There were no differences in the number of patients receiving steroids and the doses of steroids. Antibiotic prophylaxis was also equal in both groups. Postpartum endometritis, chorioamnionitis, and the latency to delivery were also equivalent between both the groups. Cesarean delivery for distress was the only different outcome, more prevalent in daytime deliveries (157 (44.7%) versus 108 (35.9%) of the nighttime ones p =.02). Neonatal adverse outcomes as well as long-term outcomes were similar between the two groups. Conclusions: In the setting of delivery at a tertiary care center, and in the era of universal use of steroids, and latency antibiotics for the management of preterm premature of membranes, there is no marked difference in pregnancy, neonatal as well as long-term outcomes for infants delivered in the daytime versus nighttime.