Association of weekend delivery with adverse neonatal outcomes: a systematic review and meta-analysis

Maternal and neonatal outcomes are key indicators of healthcare quality. However, disparities in outcomes related to hospital staffing patterns and resource availability during weekends, commonly referred to as the "weekend effect," remain a global concern. This systematic review and meta-analysis aimed to evaluate the association between weekend delivery and adverse neonatal outcomes using adjusted estimates from diverse healthcare settings worldwide.

A systematic search of major databases was conducted to identify observational studies published up to January 2026. Studies were eligible if they reported adjusted effect estimates for neonatal outcomes comparing weekend and weekday deliveries. Nine high-quality studies, with Newcastle-Ottawa Scale scores ranging from 7 to 9, were included. A random-effects meta-analysis was performed to calculate pooled adjusted odds ratios (aORs) with 95% confidence intervals (CIs). All analyses were conducted using R software version 4.4.

Nine studies were included. For neonatal mortality, weekend delivery was associated with a 4.5% increase in adjusted odds; however, this association was not statistically significant (aOR 1.045, 95% CI 0.994-1.099; I² = 0.0%). In contrast, weekend delivery was significantly associated with higher odds of neonatal intensive care unit (NICU) admission (aOR 1.199, 95% CI 1.027-1.399; I² = 94.3%), maternal obstetric infection (aOR 1.078, 95% CI 1.045-1.112; I² = 0.0%), and preterm birth among high-risk populations, including women with pregestational diabetes or advanced maternal age (aOR 1.632, 95% CI 1.518-1.756; I² = 0.0%).

Although contemporary obstetric care systems appear effective in preventing excess neonatal mortality after adjustment for case mix, significant disparities remain in important morbidity outcomes. These findings suggest that modifiable health system factors during off-hours care continue to influence perinatal outcomes and underscore the need for standardized seven-day clinical coverage to improve maternal and neonatal safety.