Timing of indicated delivery after antenatal steroids in preterm pregnancies with severe hypertension

Objectives: To evaluate the effect of the time interval between administering antenatal steroids needed to accelerate fetal lung maturity and indicated delivery in preterm pregnancies complicated by severe hypertension, as determined by maternal and perinatal outcomes. Methods: The Nova Scotia Atlee Perinatal Database was used to identify a population-based cohort of women with severe hypertension who delivered an infant between 1989 and 2002. Women were included if they received antenatal steroids and required delivery between 26 and 34 weeks gestation. Multivariate logistic regression analyses were conducted to evaluate the effect of time interval on maternal and perinatal mortality, maternal hemorrhagic and hypertension-associated morbidity, and perinatal respiratory, infectious, and prematurity-associated morbidity, while controlling for confounding variables. Results: 172 pregnancies satisfied inclusion and exclusion criteria. Betamethasone was the most commonly used corticosteroid to accelerate fetal lung maturity (95%). Among infants delivered at 26 to 34 weeks, adjusted analyses showed a reduction in risk of depression at birth (RR, 0.54; 95% CI, 0.24 to 0.97) and need for surfactant (RR, 0.50; 95% CI, 0.25 to 0.95) when the time interval from steroid administration to delivery was > 48 hours compared with ≤ 48 hours. Adjusted analyses in a subgroup of women with cesarean delivery (81% of deliveries) demonstrated no differences in rates maternal or neonatal morbidity. Conclusions: The rates of most adverse maternal and neonatal outcomes in preterm pregnancies with severe hypertension delivered at 26 to 34 weeks are not affected by timing from steroid administration to delivery. These data support the decision for delivery based mainly on obstetrical indications.