Materials and Methods: In this case-control study, 200 women were selected between April 2024 and April 2025. Based on endometriosis, patients were split into two groups: 120 infertile women without endometriosis and 80 infertile women with endometriosis. All patients had blood samples measured for antibodies to antinuclear antibodies (ANA), to anti-thyroid peroxidase (ATPO), to lupus anticoagulant (LAC), and to antiphospholipid antibodies (APLA). Ovarian reserve was evaluated by measuring anti-Müllerian hormone (AMH). Clinical signs and disease severity were recorded. The data were analyzed using SPSS version 22, with a significance level of 0.05.

Results: Patients were 34.95±5.6 years of age and had a body mass index (BMI) of 25.20±3.56 kg/m2. The Adhesion (P < 0.0001), sliding (P < 0.0001), kissing ovary (P < 0.001), and uterosacral involvement (P < 0.0001) were all significantly more frequent in the group with endometriosis. It showed that the prevalence of ANA (26.3% vs. 10.1%; P = 0.003), LAC (38.8% vs. 6.7%; P = 0.003), and ATPO (22.5% vs. 10.1%; P = 0.025) was significantly higher in the endometriosis group, while no difference was observed in APLA (P = 0.686). In patients with endometriosis, a significant decrease in oocyte count (P = 0.033) and a significant increase in cycle count (P = 0.045) were observed.

Conclusions: In this study, comparing infertile women with those without endometriosis, a significantly higher prevalence of ANA, LAC, and anti-TPO antibodies was observed in women with endometriosis, along with reduced ovarian reserve indices. These findings indicate systemic immune involvement and suggest that ovarian dysfunction may be linked to autoimmune responses. Identification and follow-up of patients with positive antibody tests may therefore be important for fertility management and the prevention of declines in ovarian reserve.