Early-Onset Sepsis in Preterm Neonates of 22-28 Weeks' Gestation: An International Cohort Study

Early-onset sepsis (EOS) is associated with increased mortality and morbidity in preterm neonates. We aim to study the epidemiology of EOS among extremely preterm neonates across a multinational neonatal registry.

A retrospective cohort study (2007-2023) of neonates born under 28 weeks' gestation from the International Network for Evaluation of Outcomes in Neonates collaboration, involving 11 national neonatal registries. The definition of EOS was blood or cerebrospinal fluid culture-positive sepsis within the first days after birth (ranging from <2 to <7 days of life). Primary outcome was mortality. Secondary outcome was major morbidities (severe neurological injury, severe retinopathy of prematurity, necrotizing enterocolitis, late-onset sepsis, or bronchopulmonary dysplasia). Univariate and multivariate analyses were performed.

Four thousand three hundred fifty-four of 130,938 (3.3%) neonates with mean (±SD) gestational age 26.1 (±1.7) weeks and birthweight 874 (±241) grams developed EOS. Rates of EOS ranged from 1.6% to 6.6% across International Network for Evaluation of Outcomes in Neonates countries. Pregnancy associated hypertension and caesarean delivery were not associated with EOS. For EOS infants the mortality rate was 35.5% and mortality or morbidity rate was 78.2%. Odds of mortality remained higher after adjustment (AOR, 2.49; 95% CI: 2.27, 2.74) along with mortality or morbidity (AOR, 1.89; 95% CI, 1.70-2.10). Severe neurological injury was the leading complications (AOR, 2.34; 95% CI, 2.11-2.59). Variations in incidence, morbidity, and mortality were also noted between countries.

EOS is common in extremely preterm neonates, varying across countries and associated with higher odds of mortality and morbidity.