Adverse neonatal outcomes associated with pregestational diabetes mellitus in infants born preterm.

Background: Pregestational diabetes mellitus is associated with a higher risk of adverse pregnancy outcomes. Based on the available data, it is unclear whether infants born preterm to mothers with pregestational diabetes mellitus are at a higher risk of adverse outcomes than other preterm infants.

Objective: This study aimed to quantify the neonatal complications associated with pregestational diabetes mellitus in infants born preterm.

Study Design: This was a retrospective cohort study of all nonanomalous singleton neonates born in Texas from 2006 to 2014. Analysis was limited to births between 24 and 36 weeks' gestation and excluded multiple births, stillbirths, fetal congenital anomalies, neonates born to mothers with gestational diabetes mellitus, and neonates born to mothers with chronic hypertension. Results were stratified by pregestational diabetes mellitus status. Neonatal outcomes of interest included infant death, neonatal intensive care unit admission, low 5-minute Apgar scores, assisted ventilation of >6 hours, surfactant administration, and seizures. Multivariate logistic regression analysis was performed to estimate the association between pregestational diabetes mellitus and neonatal outcomes controlling for potential confounding variables.

Results: After predefined exclusions, 277,210 births were analyzed, 4164 of which were to mothers with pregestational diabetes mellitus. The comparison group consisted of mothers without pregestational diabetes mellitus. The preterm infant mortality rates between the pregestational diabetic and nondiabetic groups were similar. However, after adjusting for confounding variables, there was an increased risk of infant mortality for preterm neonates born to mothers with pregestational diabetes mellitus. In infants born preterm, pregestational diabetes mellitus was associated with an increased risk of infant death, low 5-minute Apgar score, prolonged assisted ventilation, surfactant requirement, and neonatal intensive care unit admission. Neonates born before 34 weeks' gestation had an increased risk of assisted ventilation of >6 hours, neonatal intensive care unit admission, and seizure. Neonates born to mothers with pregestational diabetes mellitus in the late preterm period between 34 and 36 weeks' gestation had an increased risk of low Apgar score at 5 minutes, assisted ventilation of >6 hours, surfactant use, and neonatal intensive care unit admission.

Conclusion: Pregestational diabetes mellitus is associated with a higher risk of adverse neonatal outcomes in infants born preterm.