Newborn screening for congenital adrenal hyperplasia in Srinagarind Hospital, Khon Kaen University, Thailand

Background: Salt wasting 21-hydroxylase deficiency congenital adrenal hyperplasia (CAH) is the most common cause of adrenal insufficiency during neonatal periods. Newborn screening for CAH will improve case early detection and decrease associated morbidity and mortality. The previous nationwide incidence of CAH in 1999 was 1:19,521. To date, CAH newborn screening has not been included in national newborn screening program.

Objective: We evaluated the incidence of CAH in newborns delivered at Srinagarind Hospital.

Methods: Between September 2005 and June 2008, the filter paper blood spot 17-hydroxyprogesterone (17-OHP) tests were determined in newborns delivered at Srinagarind Hospital. The tests were concurrently performed with TSH and phenylketonuria screening in national newborn screening program of the Ministry of Public Health of Thailand. Re-evaluation with completed physical examinations, repeated blood test for serum 17-OHP and serum electrolytes were performed in newborns who had 17-OHP levels higher than cut-off values. CAH was indicated in patients who had abnormal high serum 17-OHP concentration with or without hyperpigmentation and/or ambiguous genitalia in affected females and/or electrolyte imbalance.

Results: Five thousand seven hundred seventy one of 7,147 (80.74%) live births were screened for CAH. Fourteen infants (0.24%) were recalled for re-evaluation. Eight of fourteen (57.14% response rate) infants had the repeated blood tests. Abnormal elevated serum 17-OHP concentrations were found in two infants. Only one had clinical and laboratory findings indicative of CAH. The incidence of CAH was therefore 1:5,771.

Conclusion: The incidence of CAH from newborn screening in Srinagarind Hospital was obviously higher than national incidence of Thailand. The implement of CAH screening for all neonates should be reconsidered.