Neonatal screening for congenital adrenal hyperplasia: transitory elevation of 17-hydroxyprogesterone.

Aim: The aim of the study was to identify patients with transitory elevation (TE) of 17-hydroxyprogesterone (17-OHP) using neonatal screening for congenital adrenal hyperplasia due to 21-hydroxylase deficiency (21-OHD) and to compare them with patients with 21-OHD.
Methods: This was a retrospective study of patients with high 17-OHP levels detected during newborn screening in Madrid, Spain.
Results: 17-OHP levels were significantly higher in the 33 21-OHD patients, who tended to present hyponatraemia and hyperkalemia. The TE-17-OHP group was characterized by normal initial physical examination (88.8% vs. 39.4%), lower gestational age and a higher number of stressful perinatal factors. 17-OHP levels decreased spontaneously in this group. Molecular diagnosis allowed us to discard the most frequent mutations associated with 21-OHD.
Conclusions: Newborns with slightly increased 17-OHP levels and normal results for physical examination, acid-base equilibrium, glycemia, electrolytes and perinatal stress factors should be carefully evaluated. Decisions on treatment should be postponed until these results are available.