Fig. 3

Maternal thyroid function and therapeutic course. During pregnancy, the maternal thyroid function was unstable; therefore, it was difficult to decrease the dosage of the antithyroid medication. Between the first and second trimesters, FT3 levels were normal to high, FT4 levels were low, and TSH levels were low. Elevated TSH levels were detected starting from week 33, along with a fetal goiter. Thus, the antithyroid medication dose was reduced and maintained until delivery. After delivery, hyperthyroidism was diagnosed, and the antithyroid medication dose was increased