Cutoff levels of 17-alpha-hydroxyprogesterone in neonatal screening for congenital adrenal hyperplasia should be based on gestational age rather than on birth weight.

Objective: In newborn screening programs for congenital adrenal hyperplasia, 17-alpha-hydroxyprogesterone (17OHP) cutoff levels are based on birth weight (BW) or on gestational age (GA). We investigated which approach would result in the greatest specificity and sensitivity.

Study Design: For the determination of 17OHP, a neonatal 17OHP assay was used in filter paper blood of 9492 newborns.