Endocrine Abstracts

Introduction: Thyroid carcinoma is common in young women. Radioactive iodine (RAI) therapy has been confirmed as a useful treatment in the management of differentiated thyroid carcinoma (DTC). For women with DTC, the effect of RAI therapy on gonadal and reproductive function is an important consideration. We aimed to evaluate effects of RAI therapy on ovarian function.

Method: Women younger than 40 years old and diagnosed with thyroid cancer that required RAI treatment were enrolled in this study.Patients with ovarian insufficiency were excluded. Early follicular phase serum follicle stimulating hormone (FSH) and anti-müllerian hormone (AMH) levels were measured before and 3–6 months after RAI therapy. Friedman test is used to detect changes in FSH and AMH levels by RAI therapy with time.

Results: Eighteen patients with a mean age of 31.9±4.9 years were enrolled in this study. Median AMH levels were 4.2 (2.96–17.42) ng/ml, 2.21 (0.84–3.69) ng/ml, 2.08 (0.86–6.12) ng/ml before and 3–6 months after RAI therapy, respectively. Median FSH levels were 5.5 (3.78–15.5) mIU/ml, 5.32 (4.19–35.36) mIU/ml, 6.07 (4.24–13.69) mIU/ml before and 3–6 months after RAI therapy, respectively. AMH levels before RAI were higher than after RAI (P=0.021).AMH levels after RAI at 3 and 6 months were not different. FSH levels were similar before and after RAI.

Conclusion: Anti-müllerian hormone (AMH) is considered an important marker of ovarian reserve. Ovarian reserve decreases in first 6 months after RAI therapy. Further large prospective studies are necessary to determine its predictive interest for post-treatment residual fertility.