24/7 Presence of Medical Staff in the Labor Ward; No Day-Night Differences in Perinatal and Maternal Outcomes.

 The objective of this study was to assess possible day-night differences in perinatal and maternal labor outcomes in a hospital setting with no day-night differences in the presence of experienced medical staff.  This was a retrospective study conducted over 5 years between 2008 and 2012.  This study was set at the obstetric delivery unit in a tertiary hospital.  A total of 9,143 singleton deliveries were assessed after 34 weeks of gestation and after exclusion of major congenital malformations, inductions of labor, and elective cesarean sections.  Data were collected using the hospital electronic medical records. Time periods of 8 hours were defined (daytime between 8 am and 4 pm, evening time between 4 pm and 12 pm, and nighttime between 12 pm and 8 am). Differences between the three time periods were assessed using software R Core Team (2013). Main outcome measures were neonatal birth asphyxia, neonatal intensive care unit admission, and neonatal death.  There were no differences in perinatal and maternal outcomes in the course of the day, apart from a higher incidence of third- and fourth-degree tears during the evening. Neonatal outcome after obstetric emergencies (uterine rupture, partial placental abruption, and cord prolapse) also showed no day-night differences.  Adverse nighttime-related outcomes may be avoided by the 24/7 presence of experienced medical staff.