Chronic endometritis impairs embryo implantation in patients with repeated implantation failure: A retrospective study

Objective To assess whether chronic endometritis (CE) affects embryo implantation in patients with repeated implantation failure (RIF). Materials and methods We retrospectively analyzed 126 RIF patients who were never diagnosed with CE and received no prior antibiotic therapy. Endometrial specimens obtained by endometrial scratching during mid-luteal phase were immunostained by CD138, a hallmark plasmacyte marker, to identify CE. Pregnancy outcome in RIF patients who underwent IVF-ET frozen-embryo within transfers 6 months after endometrial scratching was compared between women with and without CE. Results The prevalence of CE in patients with RIF was found to be 11.9% (15/126). Moreover, a significantly reduced clinical pregnancy rate was observed in RIF patients with CE (20% vs. 46.85%; p = 0.04). The live birth rate also exhibited a decreasing trend in RIF patients with CE, although there was no statistically significant difference (20% vs. 41.58%; p = 0.109). Conclusions CE may be involved in the failure of embryo implantation and reduced clinical pregnancy outcome in patients with RIF.