FREQUENCY OF CONGENITAL HYPOTHYROIDISM IN PRETERM AND LOW BIRTH WEIGHT NEONATES IN A TERTIARY CARE HOSPITAL

Background: Congenital hypothyroidism (CH) is a preventable cause of neurodevelopmental impairment. Preterm and low birth weight neonates are at heightened risk and may require repeat thyroid-stimulating hormone (TSH) screening to avoid missed or delayed diagnoses. Objective: To determine the frequency of CH in preterm and low birth weight neonates admitted to a tertiary care hospital and to explore its association with key perinatal variables. Study Design: Descriptive cross-sectional study. Settings: Department of Pediatrics, Chaudhry Muhammad Akram Teaching and Research Hospital, Lahore, Pakistan. Duration of Study: 3 December 2024 to 3 June 2025. Methods: A total of 165 neonates who were preterm (<37 weeks' gestation) or low birth weight (<2500 g) were enrolled through non-probability consecutive sampling. Dried blood spot specimens were analyzed for TSH using an immunoradiometric assay. CH was defined as TSH ≥20 mIU/L. Associations between CH status and age at testing, sex, gestational age, and mode of delivery were evaluated with a two-sided α of 0.05. Results: The mean gestational age was 33.29 ± 1.78 weeks, and the mean birth weight was 1841.56 ± 310.97 g. CH was detected in 10.3% (n=17/165) of neonates. There was no statistically significant association between CH and age at testing (p=0.704), sex (p=0.778), gestational age (p=0.923), or mode of delivery (p=0.189). Conclusion: A notably high frequency of CH was observed among preterm and low birth weight neonates in this tertiary care setting. These data support routine and repeat TSH screening in this high-risk population to enable timely diagnosis and initiation of therapy.