Clinical characteristics and thyroid function in complete hydatidiform mole complicated by hyperthyroidism

Area of Science:

• Endocrinology
• Gynecology
• Oncology

Background:

• Hyperthyroidism can complicate pregnancy, with complete hydatidiform mole (CHM) being a known risk factor.
• Understanding clinical predictors of hyperthyroidism in CHM is crucial for timely management.

Purpose of the Study:

• To identify clinical factors associated with hyperthyroidism at the time of CHM diagnosis.
• To evaluate thyroid function following molar evacuation.

Main Methods:

• An observational study of 137 women with CHM in Brazil (2002-2018).
• Clinical data and serum hCG, TSH, and fT4 levels were collected at presentation.
• Logistic regression and ROC curves were used to identify predictors and optimal hCG cutoffs for hyperthyroidism.

Main Results:

• 50.3% of CHM patients presented with hyperthyroidism (subclinical or overt).
• Uterine fundal height > 16 cm or > gestational age, and theca lutein cysts >6 cm were significantly associated with hyperthyroidism.
• An hCG cutoff of 430,559 IU/L predicted hyperthyroidism with 85.5% sensitivity and 83.8% specificity.
• 13% of women with hyperthyroidism experienced post-evacuation conversion to hypothyroidism.
• Thyroid-stimulating hormone (TSH) normalized within 2-3 weeks, and free thyroxine (fT4) within 2 weeks in most cases.

Conclusions:

• Clinical factors like uterine size, theca lutein cysts, and elevated hCG levels predict hyperthyroidism risk in CHM.
• Thyroid function typically normalizes rapidly post-evacuation, enabling swift cessation of beta-blockers or antithyroid drugs.