Weekend delivery and maternal-neonatal adverse outcomes in low-risk pregnancies in the United States: A population-based analysis of 3-million live births

Background Childbirth is the most common cause of hospital admission in the United States. Previous studies have shown that there might be a "weekend effect" in perinatal care, indicating that mothers and newborns whose deliveries occur during the weekends are at increased risk of having adverse outcomes. This study aims to isolate the association between the weekend delivery and maternal-neonatal adverse outcomes by investigating low-risk pregnancies in nationwide data. Methods A population-based study of all low-risk pregnancies (in-hospital, nonanomalous, term, normal birthweight, and singleton) was conducted based on US national natality data in 2017. Four maternal outcomes (ICU admission, uterine rupture, blood transfusion, and perineal laceration) and three neonatal outcomes (5-minute Apgar <7, NICU admission, and neonatal death) were defined as adverse outcomes. Logistic regression analyses were conducted to determine the association, adjusting for 23 maternal and neonatal characteristics and risk factors. Results Among 3 011 577 low-risk pregnancies, 6.0% were reported to have at least one of the maternal-neonatal adverse outcomes. Weekend deliveries were significantly associated with six maternal-neonatal adverse outcomes with an exception of neonatal death. In general, weekend deliveries were 1.13 times significantly as likely to have any of seven maternal-neonatal adverse outcomes than weekday deliveries (OR 1.13, 95% CI 1.11-1.14), being attributed to adverse outcomes of more than 4500 mother-newborn pairs. Conclusions Weekend delivery is a consistent risk factor for both mothers and babies at the national level. Furthermore, studies are needed about possible modifiable factors that mediate these associations to ensure safe childbirth regardless of the day of delivery.