Radioactive iodine effects on ovarian reserve: a systematic review and metaanalysis

Differentiated thyroid carcinoma (DTC) is common, and its rate is on the rise globally. Radioactive iodine, RAI (I-131), is widely used as an adjuvant therapy or for remnant ablation. There is growing awareness about the effects of RAI (I-131) on ovarian reserve.

This meta-analysis aimed to evaluate whether RAI therapy impairs ovarian reserve as assessed by anti-Müllerian hormone (AMH) and follicle-stimulating hormone (FSH) levels. A systematic literature search was conducted in PubMed, MEDLINE, Google Scholar, and EBSCO for relevant articles published in the English language. The literature search was conducted during October and November 2024, and the studies were included if they were published in the period from 2015 to 2024. The keywords used were ovarian reserve, ovarian function, female fertility, radioactive iodine, RAI (I-131), follicle-stimulating hormone (FSH), and anti-Müllerian hormone (AMH). MeSH terms used: Iodine Radioisotopes, Ovarian Reserve, and Thyroid Neoplasms.

Out of the two hundred and sixty-nine studies retrieved, 160 remained after duplication removal, of which 17 full texts were screened. However, only six studies (with 430 patients) were included in the final meta-analysis. AMH level were significantly lower after RAI (I-131) with a mean difference (MD) of 1.96. 95% CI, 0.53 to3.40. The levels were higher in the RAI (I-131) group after removing studies with significant heterogeneity, MD, 0.36. 95% CI, 0.17 to 0.55. FSH levels were significantly higher following RAI (I-131), MD -1.07, 95% CI, -2.02 to-0.13.

Current evidence shows a significant reduction in anti-Müllerian hormone (AMH), and significant increase in FSH levels after RAI (I-131), but data are heterogeneous. Larger prospective studies with standardized outcome measures are needed.