SCREENING OF 0.7 MILLION SWEDISH NEWBORN INFANTS FOR CONGENITAL ADRENAL HYPERPLASIA

Using filterpaper blood samples 681 000 newborns were screened for congenital adrenal hyperplasia (CAH). 17-Hydroxy-progesterone (17-OHP) was analyzed by immunoassay. By gestational age (GA) related cut-off limits it was possible to decrease the false positive rate to less than 0.03% (1:4000); the majority was preterm infants (mean GA 28 weeks). A total of 58 CAH patients were classified as true positive. Thirtyone (31) patients with CAH were detected by the screening, and in 27 patients the diagnosis was confirmed or suspected when the result of the screening test was available on day 11 after birth (median). Five (5) girls and one boy with CAH were classified as false negative. The prevalence of CAH in the screened population was 1:10 900 which does not differ from that obtained before screening was started. The sensitivity of the screening test was 0.92 and the predictive value of a positive test was 0.24. By screening it was possible to avoid serious salt loss after the age of 2 weeks. The cost of screening was approximately 2.6 USD per infant. We suggest that CAH screening should be included in the Swedish routine neonatal screening program.