Antenatal Corticosteroids and Newborn Screening for Congenital Adrenal Hyperplasia

Abstract

OBJECTIVE: To assess the effect of reported corticosteroid exposure on neonatal levels of 17-hydroxyprogesterone (17-OHP), the cortisol precursor used in newborn screening for congenital adrenal hyperplasia, in newborns weighing less than 2500 g at birth. DESIGN: A retrospective study of newborns weighing less than 2500 g at birth and exposed to corticosteroids as reported on their newborn screening card compared with newborns weighing less than 2500 g at birth and reported as not exposed to corticosteroids. METHODS: Birth weight, gestational age, age at screening, special care information, and name of screening hospital were obtained from newborn screening cards for 16 115 newborns screened in Michigan during the first 3 months of 2000. Levels of 17-OHP, measured by fluoroimmunoassay, were obtained from Michigan's Newborn Screening Program database. RESULTS: The mean 17-OHP level for the 69 low-birth-weight newborns in the corticosteroid-exposed group was 52 ng/mL, which was higher than that for the 771 low-birth-weight newborns in the unexposed group (35 ng/mL) (P<.001). Reported corticosteroid use did not decrease the number of expected borderline positive screening results for congenital adrenal hyperplasia (P>.05). Levels of 17-OHP varied by birth weight in corticosteroid-exposed and unexposed newborns. CONCLUSIONS: Corticosteroid exposure may not suppress screening 17-OHP levels. Therefore, newborn screening should not be delayed in premature newborns because of antenatal exposure to corticosteroids.