Neonatal screening for congenital adrenal hyperplasia: considerations regarding the transient rise of the 17-hydroxyprogesterone - doi:10.5020/18061230.2006.p203

Abstract

The transient rise in 17-hidroxiprogesterone (17-OHP) diagnosed by neonatal screening test (NST) may lead to the incorrect diagnosis of congenital adrenal hyperplasia. To investigate this condition, a retrospective study was conducted on medical registers of patients with this disorder and attended at a reference unit, in the last five years. Ten children (6 girls) were evaluated. Five were full-term newborns (FTN), with gestational age (GA) of 39.2±0.5 weeks and birth weight (BW) 3.2±0.3 kg; and five were preterm (PTN) with GA of 32.4±2.5 weeks and BW 1.8±0.6 kg. The 17-OHP in the NST was measured between 3-25 days (9.2±5.8 days), presenting the following results: FTN 20.1±5.9 ng/mL (< 10 ng/mL) and PTN 23.6±9.0 (< 15 ng/mL). During the follow-up, the 17-OHP returned to normal values in 7.5±2.4 months. There were no changes in serum glucose and electrolytes. None of the patients had genital ambiguity, salt-losing crisis, and family history of adrenal disorder or needed corticotherapy. It follows that NST using only two reference values for 17-OHP (FTN and PTN) may yield false-positives results. Children with rise of the 17-OHP in the NST and normal physical examination may be followed as outpatients with special attention to dehydration; and having monthly laboratory determination of 17-OHP and electrolytes. The progressive drop of 17-OHP suggests that have had a transient rise of this hormone. In these cases, it’s advisable to not initiate corticotherapy and to monitor the 17-OHP return to normality. The authors recommend an update of the 17-OHP cut-off values in the NST based on gestational age.