ESPE Abstracts

Background: Congenital Hypothyroidism stands as the most common congenital endocrine disorder in childhood and a leading preventable cause of mental retardation. Despite its prevalence, global newborn detection rates remain suboptimal. The main hurdle in implementing newborn screening in Pakistan is lack of healthcare infrastructure coupled with lack of prevalence data and economic crises. The Aga Khan University Hospital spearheaded congenital hypothyroidism screening in Pakistan in March 1987, followed by dried blood spot newborn screening in April 2019. The estimated CH incidence in Pakistan ranges from 1:1000 to 1:1600, which is much higher than the worldwide incidence of 1:2000-3000.

Objective: To determine the clinical profile and outcomes of neonates with primary congenital hypothyroidism identified through dried blood spot newborn screening program in Aga Khan University Hospital over five years from April 2019 to April 2024.

Methods: Retrospective review of data from medical records of all confirmed congenital hypothyroidism cases was done. Data including the demographics, antenatal and family history, clinical features, age at diagnosis and start of treatment, initial TSH, FT4 levels, thyroxine dose increment with age, follow-ups in the clinic, growth and neurodevelopmental outcomes were studied. Data was recorded on a structured proforma and identity was kept anonymous.

Results: 41 babies were diagnosed with congenital hypothyroidism. Incidence rate was 1 in 1000 live births. Out of all, 58% were females, 7 babies had a birth weight <2.5 kg (17%), 9 babies were preterm with gestational age >33 weeks. 8 mothers had hypothyroidism while sibling history was positive in 2 cases. DBS TSH was >20 in 27 babies (65.8%), serum TSH was >100 in 16 babies (39%) with depressed FT4 in 36.5%. Mean age at diagnosis was 8.4 days while at treatment initiation was 10.8 days. 8 babies were symptomatic at the time of diagnosis with most common symptom being prolonged jaundice followed by umbilical hernia. 2 babies had associated congenital nephrotic syndrome, one had trisomy 21, and one had imperforate anus. Follow-up showed increments in doses in 10 cases, 2 kids had isolated speech delay, 2 had developmental delay requiring neurodevelopmental evaluation while the growth of the majority (90.2%) of babies was normal.

Conclusion: Incidence of Congenital hypothyroidism was reported 1:1000 surpassing the global incidence, highlighting the urgency for early detection and treatment strategies at the government level. Most babies were asymptomatic at the time of diagnosis, making screening a mandatory tool to prevent adverse long-term growth and neurodevelopmental outcomes.