OBJECTIVE. The goal was to determine whether repeat prenatal corticosteroid treatment alters blood pressure and myocardial wall thickness in neonates.
METHODS. A randomized, double-blind, placebo-controlled trial was performed in a tertiary perinatal center. Mothers with a singleton, twin, or triplet pregnancy, at a gestational age of <32 weeks, who had received initial treatment with corticosteroid ≥7 days earlier and who were considered to be at continued risk of preterm birth were assigned randomly to receive additional weekly betamethasone or placebo treatment. One hundred forty-five infants born to 120 women were studied. Blood pressure in the first 4 weeks after birth or until hospital discharge and interventricular septal thickness and left ventricular posterior wall thickness in diastole 48 to 72 hours after birth were measured.
RESULTS. There were no differences in mean, systolic, or diastolic blood pressures between infants in the placebo and repeat steroid groups. Blood pressures of infants in both groups were similar to published normal values. There were no differences between groups in interventricular septal thickness or left ventricular posterior wall thickness in diastole. In comparison with published normal ranges, however, 24% of infants had interventricular septal thickness and 32% of infants had left ventricular posterior wall thickness of >95th percentile.
CONCLUSION. Exposure to repeat prenatal corticosteroid treatment did not increase neonatal blood pressure or myocardial wall thickness in infants who remained at risk of very preterm birth ≥7 days after an initial course of corticosteroid treatment.