The outcome of hyperemetic pregnancies complicated by transient hyperthyroidism.

Thirty-nine patients presenting with hyperemesis gravidarum were studied and the subsequent course and outcome of pregnancy between patients with normal and abnormal thyroid function was compared. Seventeen patients (43.6%) developed transient hyperthyroidism, for which a short course of antithyroid treatment was required in 2 patients. There was no difference in the outcome of pregnancy between patients with normal and abnormal thyroid function. The results suggest that while antithyroid treatment is effective for symptomatic control, it is unnecessary in the majority of patients since the condition is self-limiting, and the outcome of pregnancy not adversely affected by the transient hyperthyroidism in hyperemetic patients.