Effects of antenatal corticosteroids on blood pressure in very low birth weight infants during the first 24 hours of life

OBJECTIVE: We tested the hypothesis that prenatal glucocorticoids significantly increase mean arterial blood pressure in very low birth weight preterm infants during the first 24 hours after birth. STUDY DESIGN: Prospectively collected data from 178 inborn infants with birth weights between 500 and 1499 gm were examined. A total of 80 infants were born to mothers treated with corticosteroids (birth weight: 1057 ± 271 gm, gestational age: 28.0 ± 2.6 weeks), and 98 infants were untreated controls (birth weight: 1030 ± 280 gm, gestational age: 28.0 ± 2.8 weeks). The study setting was a university-based tertiary care center for newborn intensive care. RESULTS: Mean blood pressures on admission and at 3, 6, 12, 18, and 24 hours were significantly higher in steroid-treated infants. Steroid-treated infants received significantly less volume expansion (3.8 ± 8.5 ml/kg versus 14.4 ± 20.7 ml/kg;p < 0.001) than controls. Vasopressor support was also reduced in the steroid group (2.5% versus 11.5%; p < 0.05). CONCLUSION: Antenatal steroids are associated with both a higher mean systemic blood pressure and a decreased use of vasopressors and plasma expanders in very low birth weight infants during the first 24 hours after birth. This effect is not limited to infants of <1000 gm; it is also significant in infants with a birth weight between 1000 and 1499 gm, and is already detectable in the first hours of life. We speculate that this finding may contribute to the mechanism of steroid protection against conditions such as intraventricular hemorrhage.