Antenatal magnesium sulfate (Mg SO4) exposure and incidence of patent ductus arteriosus (PDA) in extremely low birth weight infants (ELBW)

Abstract

PATENT DUCTUS ARTERIOSUS (PDA) IN EXTREMELY LOW BIRTH WEIGHT INFANTS (ELBW) VICTOR GONZALEZ-QUINTERO, TERESA DEL MORAL, NELSON CLAURE, SILVIA VANBUSKIRK, EDUARDO BANCALARI, University of Miami, Obstetrics and Gynecology, Miami, Florida, University of Miami, Pediatrics, Miami, Florida, University of Miami, Neonatology, Miami, Florida OBJECTIVE: Antenatal exposure to Mg SO4 either for tocolysis or seizure prophylaxis can have significant clinical effects in ELBW infants. Among these, it may adversely influence the closure of the ductus arteriosus. The purpose of this study was to explore the relationship between antenatal exposure to Mg SO4 and the incidence of PDA in ELBW infants. STUDY DESIGN: A total of 952 neonates with birth weight between 500-1000 born at our institution between January 1996 and December 2003, and who survived more than 3 days were followed until death or discharge from the hospital. A research nurse prospectively collected Perinatal and hospital course data. The incidence of PDA was compared in infants exposed to Mg SO4 with those not exposed, and between infants exposed to different maternal doses of Mg SO4. Indications for the administration of Mg SO4 to the mother were preeclampsia and tocolysis. RESULTS: The incidence of PDA was significantly higher in the group of infants exposed to Mg SO4 compared to non exposed (67% vs 60%, p = 0.0178). When stratified by gestational age the differences were significant only in the group of infants with gestational age O26 weeks (58% vs 49%, p= 0.0399). There was no relationship between prenatal exposure to Mg SO4 and the duration of PDA. Logistic regression analysis to adjust for covariables confirmed the increased risk of PDA in infants exposed to Mg SO4 (OR 1.60, CI 1.18-2.16). Furthermore the risk of PDA increased with higher doses of Mg SO4 exposure (OR 1.24 CI 1.09-1.42 per 50g of Mg SO4). CONCLUSION: In ELBW, infants antenatal exposure to Mg SO4 is associate with a higher risk for PDA and this effect is dose related and more significant in the more mature infants (O26 weeks).