The impact of spontaneous versus indicated preterm birth on neonatal outcomes among extremely premature neonates.

Abstract

To investigate whether neonatal morbidity differs in spontaneous compared to indicated preterm births in extremely premature neonates. This is a retrospective cohort study including births ≤28 weeks at a single institution from 2011-2020. Births were categorized as either medically indicated or spontaneous preterm deliveries. The primary outcome was in-hospital mortality and serious morbidity in survivors. T-tests, Fisher Exact tests, Chi-squared tests, and logistic regression models were utilized as appropriate. P<0.05 was significant. Two hundred twenty-seven births were included, with two-thirds representing spontaneous births (65.6%, 149/227) and one-third categorized as medically indicated births (34.4%, 78/227). In-hospital mortality was more common in the spontaneous preterm birth group (p=0.04), while in-hospital morbidity did not significantly vary between the medically indicated and spontaneous birth groups (p=0.32). There was no difference in in-hospital morbidity or mortality by maternal race. In multivariate models of in-hospital morbidity and mortality, gestational age was the only significant predictor of adverse outcomes. Despite in-hospital mortality being more common in spontaneous preterm births, in-hospital mortality and significant morbidity are best accounted for by gestational age alone.