Neonatal screening for congenital adrenal hyperplasia: experience and results in Argentina

Abstract

Aim: To report the experience of the neonatal screening program for congenital adrenal hyperplasia (CAH) carried out in Buenos Aires, Argentina, from 1997 to 2006.

Population and methods: 17-Hydroxyprogesterone (17OHP) was measured with an immunofluorometric assay in filter paper blood samples collected at neonatal maternity discharge. Filter paper blood levels <40 nmol/l were considered normal. 17OHP levels from 40-90 nmol/l triggered a new assessment to decide on a course of action. Confirmation of CAH was made with levels >90 nmol/l. This led to clinical follow up. For preterm (PT) infants, data were adjusted according to percentiles for gestational age and/or birth weight.

Results: From 80,436 screened newborns (46.8% girls), 8848 (11%) were PT. 15 term (T) and 3 PT infants were recalled (0.022%). Nine were confirmed as having CAH (8 T and 1 PT) (female/male: 0.8; incidence 1:8937). Mean ages of screening and treatment were 5.7 and 13 days. Only 33% of affected children were clinically suspected of having CAH prior to screening. Four boys and two girls presented salt-wasting forms and severe adrenal insufficiency crises were prevented as a result of the screening.

Conclusions: Our findings confirm the benefits of CAH neonatal screening in our country with a high incidence of the classical form. Established criteria of screening and follow up allowed us to detect unrecognized affected males and females and to successfully prevent salt-wasting crises.