A review of thyroid disease in pregnancy.

Goitre is common and alterations in biochemical indices of thyroid function are invariable during pregnancy , but thyroid disease, of which hyperthyroidism is the most frequent (0,05% of 72,257 pregnancies at three Dublin Maternity Hospitals, 1979-81) is rare. Good results in terms of perinatal loss (4/112, 3.57%) has been achieved by one of us (MID) in 109 pregnancies using antithyroid drugs alone. Neonatal thyrotoxicosis occurs in one to two percent of babies born to mothers with thyroid disease. The condition is usually transient but a prolonged course may occur in up to 20 percent. Successful pregnancy is possible despite maternal hypothyroidism; three such pregnancies have been managed by one of us (MID). Clinical hyperthyroidism due to trophoblastic disease is very rare and is cured by evacuation of molar tissue. The course of thyroid cancer is not affected by pregnancy.