Corrected 17-alpha-hydroxyprogesterone values adjusted by a scoring system for screening congenital adrenal hyperplasia in premature infants.

This study investigated the use of corrected 17-alpha-hydroxyprogesterone (17-OHP) values to detect congenital adrenal hyperplasia (CAH) in newborn infants. 17-OHP concentrations in blood spots from 913 neonates were measured using a neonatal screening test. A prematurity index was calculated using a scoring system based on gestational age and birth weight. Blood spot 17-OHP concentrations divided by the sum of prematurity scores were defined as the corrected 17-OHP values. Preterm infants (<30 wk) and low birth weight infants (<1.0 kg) showed 3.9- and 3.8-fold higher blood spot 17-OHP concentrations than normal full term infants. However, no significant differences were observed in the corrected 17-OHP values between the groups. Blood spot 17-OHP levels yielded significant correlations with the prematurity index (r = 0.42, p <0.05). Positive results for CAH were obtained in 9.5% (n = 53) and 2.0% (n = 11) of 556 premature infants by the cutoffs of blood spot 17-OHP (>15.0 ng/ml) and corrected 17-OHP values (>13.0 ng/ml), respectively. Of the 53 positive subjects, 39 (73.6%) converted to negative after 1 to 5 mo without treatment. In summary, blood spot 17-OHP levels are influenced by the prematurity of newborns. Use of corrected 17-OHP values provide limited but helpful information in screening for CAH by reducing the rate of false-positive results, especially in premature infants.