Prevalence of congenital hypothyroidism in preterm neonates: a NICU-based study

Introduction: Congenital hypothyroidism (CH) is a common endocrine disorder in neonates. Early diagnosis of CH plays a key role in preventing neurodevelopmental impairment in future. Preterm neonates are at higher risk due to their immature hypothalamic-pituitary-thyroid axis. This study aimed to assess the prevalence of congenital hypothyroidism in preterm neonates admitted to the Neonatal Intensive Care Unit (NICU). Methods: This cross-sectional study was conducted in the Department of Neonatology, Combined Military Hospital, Dhaka, Bangladesh, from July 2016 to December 2016. In this study, we included 50 preterm neonates with gestational ages ranging from 28 to 37 weeks admitted to the Department of Neonatology of our study institution. Result: The mean age of neonates at sample collection was 5.38±2.66 days. The mean gestational age was 34.06±1.81 weeks. Of the 50 neonates, 27 (54%) were male and 23 (46%) were female, with a male-to-female ratio of 1:0.85. Only 4 (8%) neonates had a maternal history of thyroid disorders. The majority of neonates (50%) were between 32–34 weeks of gestation. Serum TSH and FT4 levels were within normal ranges across all gestational age groups. Only one neonate had a borderline elevated TSH level (10.70 mU/l) with a normal FT4 level, indicating no confirmed cases of congenital hypothyroidism. Conclusion: This study showed that thyroid function was within normal limits in nearly all preterm neonates, with no confirmed cases of congenital hypothyroidism. Given the potential consequences of undiagnosed thyroid dysfunction, routine screening for thyroid disorders in preterm neonates remains essential for early detection and intervention.