THE USE OF ANTITHYROID DRUGS DURING PREGNANCY*†

Abstract

RECENT studies have indicated that pregnancy with concurrent hyperthyroidism is not more frequent than might be expected from the chance co-existence of the two conditions. For many years the association was regarded as serious, but as treatment for hyperthyroidism has become more effective, there has been less cause for alarm. On the basis of a review of published cases, Gardner-Hill (1) concluded in 1929 that one half of pregnancies with concurrent hyperthyroidism ended unsuccessfully. Over the past thirty years, however, other reports (2–5) on the treatment of hyperthyroidism during pregnancy with Lugol's solution, with or without subtotal thyroidectomy, have indicated that the incidence of miscarriage and stillbirth is reduced by therapy but remains higher in thyrotoxic than in normal patients. In the most recent report on this subject (6), the hyperthyroidism was treated with antithyroid drugs followed by thyroidectomy but the incidence of fetal loss was still 33 per cent.