Follow-up and evaluation of the pregnancy outcome in women of reproductive age with Graves’ disease after 131Iodine treatment

The aims of the present study were to analyze the outcomes of pregnancy, after 131I treatment, in patients of reproductive age with Graves' hyperthyroidism and to investigate the effects, if any, of the 131I treatment on the mothers and newborns. From 2009 to 2014, 257 pregnant female patients with Graves' hyperthyroidism in the outpatients at the Department of Nuclear Medicine and 166 healthy pregnant women from the Department of Obstetrics at Sun Yat-Sen Memorial Hospital were included in our study. They were divided into a 131I therapy group (n = 130) and an anti-thyroid drug (ATD) group (n = 127) according to their therapy before conception. The neonatal gender, rate of preterm birth, body weight ratio and occurrence of low birth weight [except for higher rates of abortion (odds ratio; OR = 2.023) and cesarean delivery (OR = 1.552) in patients with Graves' hyperthyroidism] showed no statistically significant differences from those of the healthy group (P > 0.05). The level of intrauterine growth restriction did not differ between the Graves' hyperthyroidism group and the healthy group (8 vs 2, 3.0% vs 1.2%). The outcomes of pregnancy among the 131I therapy group, ATD group and healthy group also showed no significant differences. Of the patients treated with 131I, no significant differences were observed in the outcomes of their pregnancies, whether they received propylthiouracil (PTU), levothyroxine or no additional drug treatment during pregnancy. Women with hyperthyroidism who were treated with 131I therapy could have normal delivery if they ceased 131I treatment for at least six months prior to conception and if their thyroid function was reasonably controlled and maintained using the medication: anti-thyroid drug and levothyroxine before and during pregnancy.