Maternal and neonatal intrapartum outcomes in the UK are similar during "in-hours," when a senior obstetrician is scheduled to be present on the labour ward, and "out-of-hours," when care is managed by other members of the obstetric team, according to a study published in PLOS Medicine. The multicenter cohort study, conducted by Hannah E. Knight of the Royal College of Obstetricians and Gynaecologists / London School of Hygiene and Tropical Medicine, UK, and colleagues, found no differences in Apgar scores, cord pH, or postpartum bleeding, small differences in caesarean section and instrumental delivery, and weak evidence for fewer severe perineal tears following out-of-hours delivery.

Concerns have been raised that a lack of senior obstetricians on labour wards outside normal working hours may lead to worse outcomes among mothers and babies. To identify associations between senior obstetric presence and intrapartum health outcomes, Knight and colleagues analyzed 12 months' electronic patient data and staffing rotas (schedules) from 19 obstetric units in the UK (87,501 singleton live births). They found no difference between out-of-hours and in-hours deliveries in the rate of babies with a low Apgar score 5 minutes after birth (1.33% versus 1.25%, adjusted odds ratio [OR] 1.07; 95% confidence interval [CI]I 0.95 to 1.21) or low cord pH (0.94% versus 0.82%; adj. OR 1.12; 95% CI 0.96 to 1.31) or in the rate of mothers with severe postpartum bleeding (2.4% versus 2.35%; adj OR 1.04; 95% CI 0.94 to 1.16). Women who delivered out-of-hours had slightly lower rates of intrapartum cesarean section (12.7% versus 13.4%, adj. OR 0.94; 95% CI 0.90 to 0.98) and of instrumental delivery (15.6% versus 17.0% adj. OR 0.92; 95% CI 0.89 to 0.96); 3.6% of women who had an in-hours vaginal delivery had a severe perineal tear versus 3.3% of women who delivered out-of-hours (adj. OR 0.92; 95% CI 0.85 to 1.00).

The accuracy of these findings may be limited by the use of scheduled work rotas to determine when senior obstetricians were present on labour wards rather than information about their actual presence at each delivery. Additionally, differences may result from bias by indication, as obstetric teams may prioritize higher risk patients during in-hours. The authors state that, "taken together, the available evidence provides some reassurance that the current organisation of maternity care in the UK allows for good planning and risk management. However there is a need for more robust evidence on the quality of care afforded by different models of labour ward staffing."