Comparative Analysis of Hyperbilirubinemia Between Congenital Hypothyroidism and Euthyroidism in Neonates in Rawalpindi, Pakistan

INTRODUCTION: Neonatal hyperbilirubinemia is a prevalent clinical observation that, if persistent or severe, may suggest underlying endocrine abnormalities such as congenital hypothyroidism (CH). Thyroid hormones play a crucial role in liver function and the metabolism of bilirubin. OBJECTIVE: This study aimed to evaluate blood bilirubin and thyroid stimulating hormone (TSH) levels in neonates diagnosed with CH compared to those with normal thyroid function (euthyroid). MATERIAL AND METHODS: A comparative cross-sectional observational study was conducted at Majeed Medical & Gynae Complex and Farid Medical Family Hospital in Rawalpindi, Pakistan. A total of 200 neonates, aged 1-30 days, were included in the study, comprising 100 confirmed cases of CH and 100 controls. The clinical features and demographics of patients were recorded using a structured interview questionnaire. Serum bilirubin and TSH levels were measured using automated Roche analyzers (C-311 and E-411). Data were analyzed utilizing IBM SPSS Statistics for Windows, version 25 (IBM Corp., Armonk, New York, United States) and GraphPad Prism (Dotmatics, Boston, Massachusetts, United States). RESULTS: Prolonged jaundice was the most prevalent (74%) clinical finding among the CH group. Mean bilirubin (total, direct, and indirect) levels and TSH levels were analyzed using an independent t-test, with a significance threshold set at p < 0.01. A positive significant correlation exists between TSH levels and bilirubin (total and indirect) concentration in the hypothyroid group, with a p-value of < 0.01. These findings highlight the clinical significance of timely newborn TSH screening and the early administration of levothyroxine to mitigate jaundice-related morbidity and prevent unnecessary phototherapy or extended hospitalization. CONCLUSION: The current study concludes that newborns with CH have markedly increased all types of bilirubin levels relative to euthyroid newborns, and there is a statistically significant positive correlation between TSH levels and bilirubin levels (total and indirect).