Relationship Between Antenatal Steroid Administration and Blood Pressure Regulation in Preterm Infants 1054

Abstract

Increases in neonatal blood pressure (BP) have been reported to occur with antenatal steroid (ANS) administration for fetal lung maturation in some, but not all reports. Prior to 5/1/94, ANS were used rarely at Parkland Memorial Hospital. However, after that date ANS were commonly used for pregnancies between 24-34wk gestation. To study the relationship between ANS use and neonatal BP regulation in the first 72h after birth, we examined infants with birth weight (BW) ≤1500g. 70 neonates born between 5/1/94 and 4/30/95 were exposed to ANS (Group I) and were compared with 46 matched non-exposed infants born between 5/1/93 and 4/30/94 (Group II). Infants were matched for BW(1166±253g vs 1100±241g; mean±SD), gestational age(28.7±2.1wks vs 28.9±1.8wks), gender and race. The groups were comparable for route of delivery, method of measuring BP (direct vs oscillometric), frequency of RDS, surfactant Rx, need for assisted ventilation, airleak, and fluid intake. There were no significant differences between Groups for systolic (SBP), diastolic (DBP) or mean (MBP) BP at 1, 6, 12, 24, 48 and 72h after birth (Table:mmHg). Further, the need for volume and/or pressor support did not differ significantly, 11.4% vs 6.5%, respectively. When only Group I infants whose mothers received ≥3 doses of ANS (N=35) were examined, there still were no differences between groups. BP differences were not observed when infants with BW ≤750g or≤1000g were analyzed. We conclude from these results that ANS did not modify the initial BP, subsequent BP measurements during the first 72h after birth, the rate of rise of neonatal BP in the first 72h postnatally, or the use of volume expanders or pressor agents in infants ≤1500g BW.