Systemic Inflammation and Hyperprolactinemia as Determinants of Progesterone Receptor Gene Expression in Recurrent Pregnancy Loss with Endometriosis

Background & Objective: Recurrent Pregnancy Loss (RPL) in women with endometriosis involves immune and hormonal dysregulation affecting Progesterone Receptor (PGR) signaling. Systemic inflammation and elevated prolactin may impair this pathway and contribute to pregnancy failure. This study was conducted with aim to evaluate the association of serum Interleukin-6 (IL-6), prolactin, and Progesterone Receptor (PGR) gene expression, and their diagnostic potential.Materials & Methods: This case-control study was conducted on 250 women (125 with RPL and endometriosis; 125 controls). Serum IL-6 and prolactin were measured by ELISA, and PGR mRNA expression was quantified using real-time PCR. Group comparisons were performed using non-parametric tests. Correlation, logistic regression, and ROC analyses were applied. P<0.05 was considered statistically significant.Results: IL-6 and prolactin levels were significantly higher, while PGR expression was significantly lower in cases compared to controls (P<0.001). PGR expression showed the highest diagnostic performance, followed by prolactin and IL-6. IL-6 and prolactin were negatively associated with PGR expression, and prolactin remained an independent predictor after adjustment.Conclusion: These findings demonstrate that inflammatory and hormonal alterations are associated with reduced progesterone receptor expression, indicating their potential role in RPL among women with endometriosis.