Thyroid Hormone Levels and Its Co-relation With Human Chorionic Gonadotropin in Patients With Molar Pregnancy

Introduction Gestational trophoblastic disease (GTD) is characterized by abnormal trophoblastic proliferation, with hydatidiform mole being its most common form. Markedly elevated serum human chorionic gonadotropin (hCG) concentrations in molar pregnancy can stimulate thyroid-stimulating hormone receptors, resulting in thyroid dysfunction. This study aimed to evaluate thyroid hormone levels and their correlation with serum β-human chorionic gonadotropin (β-hCG) concentrations in patients with molar pregnancy and to compare thyroid function between complete and partial hydatidiform mole. Materials and methods This prospective observational study was conducted in the Department of Obstetrics and Gynaecology, Srirama Chandra Bhanja (SCB) Medical College and Hospital, Cuttack, Odisha, India, from January 2022 to December 2023. Eighty-eight women with histopathologically confirmed hydatidiform mole were included after excluding 26 patients who had received initial treatment elsewhere and were referred exclusively for oncological management. Serum β-hCG, thyroid-stimulating hormone (TSH), free triiodothyronine (free T3), free thyroxine (free T4), total triiodothyronine (total T3), and total thyroxine (total T4) were measured before uterine evacuation. Thyroid hormone profiles were compared between complete and partial mole, and correlations between serum β-hCG and thyroid hormone parameters were analyzed using Pearson's correlation coefficient. Results Among 15,844 deliveries, 88 women with histopathologically confirmed hydatidiform mole were analyzed, yielding a hospital-based frequency of 5.5 per 1,000 deliveries. Complete mole constituted 57 (64.8%) cases and partial mole 31 (35.2%). Patients with complete mole had significantly lower TSH (0.82±0.71 vs. 1.96±0.82 µIU/mL; p<0.001) and significantly higher free T3, free T4, total T3, total T4, and β-hCG levels than those with partial mole (all p<0.001). Serum β-hCG demonstrated a significant negative correlation with TSH (r=-0.61; p<0.001) and positive correlations with free T3 (r=0.73), free T4 (r=0.69), total T3 (r=0.65), and total T4 (r=0.67) (all p<0.001). Conclusion Complete hydatidiform mole was associated with significantly higher serum β-hCG concentrations and more pronounced thyroid dysfunction than partial hydatidiform mole. Serum β-hCG concentrations demonstrated a significant negative correlation with TSH and positive correlations with free and total T3 and T4 levels, supporting a close association between trophoblastic activity and thyroid function. These findings suggest that thyroid dysfunction may be particularly relevant in women with complete hydatidiform mole or markedly elevated serum β-hCG concentrations; however, larger multicentric studies with adjustment for potential confounding factors and longitudinal follow-up are warranted to clarify the clinical significance of these associations.