A study of maternal hypothyroidism on neonatal thyroid profile and outcome

Background: Maternal hypothyroidism is one of the most common endocrine disorders during pregnancy and is associated with adverse fetal and neonatal outcomes. Early detection and management are critical, as thyroid hormone deficiency during intrauterine life may lead to irreversible neurodevelopmental impairment. Methods: This hospital-based observational study was conducted at Government Medical College, Cuddalore, from April 2023 to October 2024. A total of 100 neonates born to mothers diagnosed with hypothyroidism were enrolled. Maternal thyroid profiles were reviewed antenatally. Neonatal thyroid function tests, including serum TSH and free T4, were performed at 72 hours of life. Abnormal results were re-evaluated after two weeks. Data were analysed using STATA version 16 and Microsoft excel, employing descriptive statistics. Results: Among the neonates studied, 7.07% exhibited elevated TSH levels (>10 mIU/l), and 2% required levothyroxine therapy. Preterm birth was observed in 35% of cases, and 29% required NICU admission. Low birth weight (LBW) and jaundice were the most common clinical findings. Congenital anomalies were rare, with only one case of bilateral congenital talipes equinovarus reported. Conclusions: Maternal hypothyroidism has a measurable impact on neonatal thyroid function and early neonatal outcomes. Universal antenatal thyroid screening and targeted neonatal follow-up are essential to identify transient or delayed-onset hypothyroidism and prevent long-term neurodevelopmental sequelae.