Short-Term Outcomes of Early-Term Versus Full-Term and Late-Term Neonates: A Systematic Review and Meta-Analysis.

Abstract

Early-term births constitute 15%-31% of global births; its impact on neonates is under-recognised. To systematically synthesise current evidence comparing short-term neonatal outcomes between early-term and full-/late-term births globally and in low- and middle-income countries (LMICs). PubMed and Embase databases were searched from inception to 13 March 2025. Studies comparing short-term neonatal outcomes (e.g., morbidity, respiratory complications) among early-term (37-38 weeks' gestation), full-term (39-40 weeks) and late-term (41 weeks) births were included. Studies involving multiple pregnancies were excluded. Using PRISMA guidelines, two investigators independently screened studies, extracted data and assessed risk of bias. Meta-analyses employed a random-effects model to estimate pooled odds ratios (ORs) with 95% confidence intervals (CIs). Thirty-five studies, medium to high quality, from 15 countries (n = 13 784 259) were included. Eight studies (n = 75 081) were from LMICs. Early-term neonates had higher risks of respiratory distress syndrome (OR 2.85, 95% CI: 2.09-3.90), transient tachypnoea of the newborn (OR 2.00, 95% CI: 1.65-2.42) and composite respiratory morbidities (OR 1.75, 95% CI: 1.48-2.08) compared to full-term and late-term neonates. In LMICs, early-term neonates had an even higher risk of respiratory distress syndrome (OR 4.77, 95% CI: 1.83-12.44). However, limited data from LMICs reduced the generalisability of findings. The need for mechanical ventilation (OR 2.08, 95% CI: 1.83-2.38), continuous positive airway pressure (OR 2.41, 95% CI: 1.88-3.09) and oxygen therapy (OR 1.88, 95% CI: 1.48-2.39) was also higher in early-term neonates. Early-term neonates face higher risks of short-term adverse consequences, underscoring the need for heightened vigilance in perinatal management strategies to optimise outcomes for this vulnerable population. CRD42024556551 (https://www.crd.york.ac.uk/prospero/display_record.php?RecordID=556551).