Immature adrenal steroidogenesis in preterm infants.

Screening for congenital adrenal hyperplasia is associated with a high rate of false positive results in preterm infants. Some RIA studies have detected elevated levels of 17 alpha-hydroxy-progesterone in severely ill preterm infants. However, because the antisera used with RIAs have a high degree of cross-reactivity, RIA results may not be reliable. Adrenal steroidogenesis was evaluated in 33 preterm infants born at less than 32 weeks' gestation using reversed-phase high performance liquid chromatography. 17 alpha-hydroxyprogesterone, 11-deoxycortisol, and/or corticosterone were detectable temporarily at about 29 weeks of equivalent gestational age in 27 of 33 preterm infants. Levels of cortisol and cortisone were markedly decreased in 4 of 16 infants whose mothers had received steroids. These findings suggest that the activities of 21-hydroxylase, 11 beta-hydroxylase, and 18-hydroxylase are decreased at about 29 weeks of equivalent gestational age. Steroid levels should be carefully monitored in preterm infants with elevated intermediate steroids and preterm infants whose mothers receive steroids before delivery using reversed-phase high performance liquid chromatography.