Early infant death higher in night births

Although the risk that a newborn will die during the first week of life is now extremely small, the chances of early infant death are slightly higher among babies born during night time. Recent research shows that obstetric and neonatal care during night time may need additional skilled and experienced staff to ensure safe deliveries. Previous studies have found that infants born at night and during weekends and holidays have an increased risk of death at birth. However, these associations may be confounded by the distribution of high-risk deliveries according to time of birth.The researchers from the Department of Medical Epidemiology undertook a population-based study of 694,888 vaginal deliveries in Sweden between 1991 and 1997. They estimated relative risks of intrapartum (death at the time of labour and delivery) and early neonatal death according to the hour, day and month of delivery. Estimated risk ratios were adjusted for gestational age, birth weight for gestational age, malformations, induction of labour, breech presentations and year of birth.
Infants from high-risk deliveries were more often delivered during daytime. In comparison with infants born during daytime, those born at night were at increased risk of early neonatal death but not intrapartum death. The authors found that infants' risk of early death, regardless of their time of birth, was very low. Among infants born during the day, approximately 1 in 650 died during the first week of life; among births at night, that figure increased slightly to 1 in 570. Comparing these rates, the authors report that infants who are born during the night were 28% more likely to die during the first week of life than babies born during the day. They add that they did not observe a similar increase in infant deaths during childbirth at night relative to daytime births, suggesting that night time factors may only affect early infant care, and not deliveries themselves. Hence, infants born at night may be at increased risk of early neonatal death.

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