Hypothyroidism after cancer and the ability to meet reproductive goals among a cohort of young adult female cancer survivors

Objective To determine whether developing hypothyroidism after cancer treatment is associated with a decreased probability of women being able to meet their reproductive goals. Design A population-based cohort study. Setting Not applicable. Patient(s) A total of 1,282 cancer survivors, of whom 904 met the inclusion criteria for the analysis. Intervention(s) None. Main Outcome Measure(s) Three outcomes that may indicate reduced fertility, which include failure to achieve desired family size, childlessness, and not achieving pregnancy after at least 6 months of regular unprotected intercourse. Result(s) We used data from the Furthering Understanding of Cancer Health and Survivorship in Adult (FUCHSIA) Women's Study to examine the association between being diagnosed with hypothyroidism after cancer and meeting reproductive goals. After adjusting for age and other potential confounders, women reporting hypothyroidism after cancer treatment were twice as likely to fail to achieve their desired family size (adjusted odds ratio [aOR] 1.91; 95% confidence interval [CI], 1.09, 3.33) and be childless (aOR 2.13; 95% CI, 1.25, 3.65). They were also more likely to report having unprotected intercourse for at least 6 months without conceiving (aOR 1.37; 95% CI, 0.66, 2.83). Conclusion(s) Although cancer treatments themselves are gonadotoxic, it is important to consider other medical conditions such as hypothyroidism that occur after cancer treatment when counseling patients on the risks for impaired fertility or a shortened reproductive window.