Performance Evaluation of Newborn Screening for Congenital Adrenal Hyperplasia: A Single Health System Clinical Audit in Pakistan

Congenital adrenal hyperplasia (CAH) is an autosomal recessive disorder most commonly caused by 21-hydroxylase deficiency and can lead to life-threatening adrenal crises in infancy if not detected early. In Pakistan, the true incidence of CAH remains unknown due to the absence of national newborn screening programs. This study evaluated the effectiveness of a CAH newborn screening program introduced in 2021 at tertiary and secondary care centers in Pakistan. A retrospective cohort analysis included newborns screened between January 2021 and August 2025 using dried blood spot (DBS) 17-hydroxyprogesterone (17-OHP) testing. During the study period, 39,729 live births occurred, of which 34,621 newborns (87.1%) underwent screening. A total of 189 infants (0.55%) screened positive. Five infants were confirmed to have salt-wasting CAH; three, identified through population-based screening alone, yielded an incidence of 7.6 per 100,000 live births. The positive predictive value was 2.65%, reflecting a high false-positive rate, particularly among premature infants, while no false-negative cases were identified during the available follow-up period. This study demonstrates the feasibility of CAH newborn screening in a resource-limited setting and provides the first incidence estimates from a Pakistani hospital cohort.