Outcomes of singleton preterm very low birth weight infants born to mothers with pregnancy-induced hypertension

The association between maternal pregnancy-induced hypertension (PIH) and neonatal mortality and morbidities in preterm infants has not been consistent. This study aimed to evaluate the influence of maternal PIH on mortality and morbidities in singleton infants with very low birth weight born before 30 weeks of gestational age using the Korean Neonatal Network (KNN) database. A total of 5340 singleton infants with very low birth weight were registered in the KNN registry, who were born at 23(+0) to 29(+6) weeks of gestational age between January 2015 and December 2020. Baseline characteristics and neonatal mortality and morbidities were compared between infants with PIH and non-PIH mothers. After adjustment for potential confounders, infants with PIH mothers had significantly higher odds of respiratory distress syndrome (OR 1.983; 95% CI 1.285-3.061, p = 0.002) and bronchopulmonary dysplasia (OR 1.458; 95% CI 1.190-1.785, p < 0.001), and severe bronchopulmonary dysplasia (OR 1.411; 95% CI 1.163-1.713, p < 0.001) than infants with non-PIH mothers, while there were no significant differences in severe intraventricular hemorrhage, periventricular leukomalacia, retinopathy of prematurity, or death during neonatal intensive care unit admission between infants with PIH and non-PIH mothers. This study showed that preterm infants with PIH mothers had an increased risk of neonatal respiratory morbidities, including respiratory distress syndrome and bronchopulmonary dysplasia.