Abnormal thyroid function in hyperemesis gravidarum.

Thyroid function was evaluated in 41 consecutive women with hyperemesis gravidarum (HG). In 11, increased free thyroxin concentrations (FT4) were measured. After one week of conservative therapy, 4 patients with persistent emesis were treated with antithyroid agents. Three of these 4 displayed other signs of hyperthyroidism. Emesis resolved in the other 7 patients within a week of conservative therapy. FT4 levels also returned to normal in these 7 patients within several weeks. Thyrotropin-releasing hormone (TRH) was administered to 10 of the 11 patients. Abnormal TSH responses, suggesting varying degrees of autonomous thyroid function were noted in all 4 patients treated with antithyroid drugs and in 3 of the untreated patients. Underlying clinical signs and symptoms of hyperthyroidism should be sought in patients with HG. In the presence of persistent emesis, despite conservative therapy of at least one week's duration and the presence of abnormal thyroid function studies, the use of antithyroid agents should be considered.