Investigation of the effect of TNF-α levels on infertility duration and infertility characteristics in endometriosis patients presenting with infertility complaints.

BACKGROUND

Endometriosis is a chronic inflammatory disorder frequently associated with infertility. Tumor necrosis factor-alpha (TNF-α) is involved in inflammatory pathways; however, the clinical relevance of serum TNF-α in relation to infertility duration and ovarian reserve remains uncertain.

METHODS

This prospective comparative study included 70 infertile women aged 20-37 years: 35 women with clinically and/or radiologically diagnosed endometriosis and 35 age-matched infertile controls with unexplained infertility and no clinical or imaging evidence of endometriosis. Serum TNF-α was measured using enzyme-linked immunosorbent assay. Hormonal parameters, including anti-Müllerian hormone (AMH), were obtained from third-day menstrual-cycle samples retrieved from clinical records. Associations between TNF-α, infertility duration, AMH, and clinical characteristics were evaluated. Exploratory adjusted analyses were performed for log-transformed TNF-α and AMH.

RESULTS

Serum TNF-α levels were higher in the endometriosis group than in controls (median [IQR], 235.49 [124.33-390.31] vs. 64.58 [58.91-76.52] ng/L; p < 0.001). AMH levels were lower in the endometriosis group in unadjusted analysis (2.05 [1.67-3.41] vs. 3.30 [2.26-3.66] ng/mL; p = 0.029). After adjustment for age, BMI, smoking status, and previous surgical history, endometriosis group status remained associated with log-transformed TNF-α (β = 1.386, 95% CI 1.114 to 1.657; p < 0.001), whereas the association with AMH was attenuated (β=-0.824, 95% CI -1.817 to 0.169; p = 0.102). TNF-α was not associated with infertility duration or AMH within the endometriosis group.

CONCLUSIONS

Serum TNF-α was elevated in infertile women with clinically and/or radiologically diagnosed endometriosis but was not associated with infertility duration, AMH, or selected clinical characteristics. The high discriminatory performance observed in ROC analysis should be interpreted as exploratory because of the modest sample size, clinical/radiologic case definition, potential selection bias, and lack of external validation. Serum TNF-α may reflect systemic inflammatory activity rather than infertility severity or ovarian reserve impairment.