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

## TL;DR

This study compares bilirubin and thyroid hormone levels in newborns with congenital hypothyroidism and normal thyroid function, finding higher bilirubin levels in hypothyroid infants.

## Contribution

The study establishes a significant correlation between TSH levels and bilirubin concentrations in neonates with congenital hypothyroidism.

## Key findings

- Newborns with CH had significantly higher total, direct, and indirect bilirubin levels compared to euthyroid infants.
- A strong positive correlation was found between TSH levels and total and indirect bilirubin concentrations in CH neonates.
- Early TSH screening and levothyroxine treatment are recommended to reduce jaundice-related complications in CH infants.

## Abstract

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).