Coexistence of endometriosis and thyroid autoimmunity in infertile women

Objectives: The objective of the study was to evaluate the prevalence and impact of impaired thyroid-stimulating hormone (TSH) levels on the reproductive outcomes of in vitro fertilization patients diagnosed with endometriosis and compared to controls without endometriosis.Design: This is a retrospective cohort study on prospectively collected data.Setting: The study was conducted at tertiary care university hospital.Participants: Participants were infertile women with histopathological diagnosis of endometriosis.Methods: For 12 months (January 2018 to January 2019), women were deemed suitable and subsequently divided according to serum TSH levels above or below 2.5 mIU/L and compared to patients without endometriosis.Needed sample size was at least 41 patients for each cohort of women.Co-primary outcomes were the live birth rate (LBR), clinical pregnancy rate (CPR), and pregnancy loss rate (PLR).Results: Overall, 226 women (45 with endometriosis and 181 controls without endometriosis) were included.Diagnoses of Hashimoto thyroiditis were significantly more frequent in women with rather than without endometriosis (14/45 [31.1%] vs. 27/181 [14.9%]; p = 0.012).Similarly, in women with endometriosis, Hashimoto diagnosis rates were higher with TSH ≥2.5 mIU/L compared to TSH <2.5 mIU/L (9/ 15 [60%] vs.5/30 [16.6%]; p = 0.001) so were the Hashimoto diagnosis rates in control group (women without endometriosis) with TSH ≥2.5 mIU/L compared to TSH <2.5 mIU/L (17/48 [35.4%] vs. 10/133 [7.5%], respectively; p = 0.001).Effect size analysis confirmed an increased risk of Hashimoto thyroiditis in women with endometriosis and TSH ≥2.5 mIU/ L compared to women with endometriosis and TSH <2.5 mIU/L (risk ratio [RR] 3.60 [95% CI 1.46-8.86])and in women with endometriosis and TSH ≥2.5 mIU/L compared to non-endometriotic euthyroid patients (RR 7.98 [95% CI 3.86-16.48]).Dysmenorrhea risk was higher in endometriotic euthyroid women compared to euthyroid patients with karger@karger.