Neonatal screening for congenital adrenal hyperplasia in North-Eastern Italy: a report three years into the program.
OBJECTIVE
To evaluate the incidence of congenital adrenal hyperplasia (CAH) in the Northern Italian population and the efficiency of the North-Eastern Italy screening program. To adjust cut-off levels for 17-hydroxyprogesterone (17-OHP) in relation to gestational age and birth weight, comparing the benefits in terms of reduction of recall rates with the two approaches and ultimately choosing the better of the two.


METHODS
Since September 2001, blood samples from neonates born in North-Eastern Italy have been screened with a fluoroimmunoassay method for 17-OHP determination (DELFIA). A preliminary cut-off level of > or = 30 nmol/l was set both for term and preterm newborns. The values of 17-OHP were analysed using statistical methods in relation to gestational age and birth weight in order to modify the cut-off on the basis of our data.


RESULTS
After 33 months of screening we screened 128,282 newborns and detected 6 affected babies. During the first 8 months of screening among the recalled babies, 89.6 and 78.1% were preterm and low-birth-weight newborns, respectively, with a recall rate of 2.59% for premature neonates and of 4.94% for babies with birth weights < 2,500 g. We chose a new cut-off value of 50 nmol/l for preterm newborns only and, after 4 months, the recall rate was reduced to 0.83% for these infants and to 1.83% for low-birth-weight infants.


CONCLUSIONS
After 33 months of screening for CAH in North-Eastern Italy, we report an incidence of 1:21,380. In 5 out of 6 affected babies, the diagnosis was established only after a positive screening test, which prevented a severe salt-wasting crisis in these babies. The cut-off level related to gestational age led to a significant reduction in the number of false-positives among preterm babies.We therefore intend to continue with the screening program for CAH in North-Eastern Italy, keeping a gestational-age-related cut-off in the hope that our data may encourage a national screening program for CAH.
Cavarzere
Paolo
P
Department of Pediatrics, University of Verona, Verona, Italy. paolocavarzere@yahoo.it
Camilot
Marta
M
Teofoli
Francesca
F
Tatò
Luciano
L
D019326:17-alpha-Hydroxyprogesterone / Q000097:blood; D000312:Adrenal Hyperplasia, Congenital / Q000097:blood / Q000453:epidemiology*; D005189:False Positive Reactions; D005260:Female; D005865:Gestational Age; D006801:Humans; D015994:Incidence; D007231:Infant, Newborn; D007558:Italy; D008297:Male; D015997:Neonatal Screening
D019326:17-alpha-Hydroxyprogesterone