Thyroid function in gestational trophoblastic tumors.

Thyroid function was assessed in a total of 15 cases, 7 of whom had choriocarcinoma and 8 hydatidiform mole, by measuring free T3, free T4, thyroxin-binding globulin (TBG), basal thyroid-stimulating hormone (TSH) and after the thyrotropin-releasing hormone test (delta TSH). Free T3, free T4 and TBG were investigated in the same number of healthy women within the first three months of pregnancy. Only 13.4% of the cases presented elevated levels of free T3 and T4 and TBG; TSH and delta TSH were within normal limits. Both thyroid hormones and TBG returned to within normal limits when beta-human chorionic gonadotropin became undetectable. One patient was found to be hypothyroid. Comparison with the control group showed no significant differences except in TBG levels, which were higher in controls. A significant, direct correlation was found between levels of free T3 and T4 and TBG and the pattern of human chorionic gonadotropin.