In some cases of thyroid cancer, radioactive iodine therapy is needed after surgery to remove thyroid gland. Currently, the American Thyroid Association recommends women to wait at least 6 months to become pregnant after radioactive iodine therapy. This study was done to evaluate risk of abortion, premature birth, and birth defect after radioactive iodine therapy for thyroid cancer.
THE FULL ARTICLE TITLE
Kim HO et al. 2019 Association Between Pregnancy Outcomes and Radioactive Iodine Treatment After Thyroidectomy Among Women With Thyroid Cancer. JAMA Int Med. Epub 2019 Oct 21. PMID: 31633736
SUMMARY OF THE STUDY
A total of 111,459 women between 20-49 years of age, who had a thyroidectomy for thyroid cancer in South Korea between January 2008 and December 2015 were identified from an insurance database. Among these, 51,976 women (radioactive iodine therapy group) had radioactive iodine therapy treatment and 59,483 women (surgery group) did not. Pregnancy outcomes studied included abortion (both miscarriage and induced), premature birth, and birth defects.
The average age at thyroidectomy or radioactive iodine therapy was 39.8 years in the whole group. A total of 10,842 (9.7%) women became pregnant after treatment (9.4% in the radioactive iodine therapy and 10% in the surgery group). These women were generally younger than the whole group (mean age 31.2 years for the radioactive iodine therapy group and 31.5 years for the surgery group at treatment). The time from treatment to pregnancy was longer in the radioactive iodine therapy group (22 months) compared to the surgery group (25.3 months). The pregnancy rate was lower within the first 12 months after treatment in the radioactive iodine therapy group compared to the surgery group (0.7% vs 2.0% at 0-5 months and 1.4% vs 1.9% at 6-11 months after treatment). There was no significant differences in the rates of abortion, premature birth, or birth defects between the radioactive iodine therapy and surgery groups.