Objective To characterise the association between weekend (Saturday and Sunday) deliveries of very low birthweight (VLBW) infants and delivery room outcomes in the ‘golden hour’ after birth.

Design and setting A retrospective cohort study using California Perinatal Quality Care Collaborative data from participating neonatal intensive care units.

Patients The study population after exclusions was 26 515 VLBW infants born in California from 2010 to 2016.

Main outcome measures Delivery room outcomes assessed included: chest compressions, epinephrine, intubation prior to continuous positive airway pressure ventilation, 5 min Apgar <4, admission hypothermia and death within 12 hours. To adjust for potential confounders, we fit multivariate regression models controlling for two sets of infant, maternal and hospital characteristics.

Results Infants delivered on weekends were less likely to have been prenatally diagnosed with intrauterine growth restriction but were otherwise not significantly different in gestational age, ethnicity, sex or maternal risk factors than those born during weekdays. Caesarean deliveries were less common on weekends, while vaginal deliveries were consistent across all days. After adjusting for sex and race, weekend delivery was associated with delivery room chest compressions (OR: 1.12, 95% CI 1.02 to 1.24) and lower 5 min Apgar (OR: 1.11, 95% CI 1.01 to 1.21).

Conclusion In this population-based study of VLBW infants, there was an increase in chest compressions for infants born on the weekend. More research is needed on the differences between populations born on weekdays versus weekends, and how these may contribute to observed associations.