Pregnancy outcome after treatment with radioiodine for differentiated thyroid carcinoma.

The aim of the study was to investigate the influence of radioiodine (RAI) therapy on pregnancies and the health status of children born to mothers who had received therapeutic doses of I-131 for differentiated thyroid carcinoma (DTC). Gestational histories of 76 women treated for DTC from 1971-2005 were retrospectively analyzed. The outcome of 49 pregnancies after RAI was: 35 children (72%), 5 (10%) miscarriages and 9 (18%) induced abortions. RAI did not adversely affect the rate of successful delivery and live birth demographics. Congenital malformation and first year mortality were not observed. The children's ages range from 1 month to 29 years (chi+/-SD=8.0+/-8.4). A higher therapeutic dose (>100 mCi) did not significantly alter the pregnancy outcome. There is no reason to discourage females treated with 1-131 from becoming pregnant. Patients should avoid pregnancy after RAI administration for 1 year.