Prevalence of chronic endometritis in patients with endometrial polyps and unexplained infertility

Abstract

To assess the prevalence of chronic endometritis (CE) in patients with endometrial polyps and unexplained infertility compared to patients without history of infertility. Retrospective cohort study. We evaluated patients underwent hysteroscopic polypectomy in the period of 2015 to 2018. The inclusion criteria were age 25-42 and histologically confirmed endometrial polyps. Patients with cycle day 3-5 FSH > 10 mIU/mL, with intrauterine devices, history of repeated implantation failure and recurrent pregnancy loss, autoimmune diseases, suspected placental residua, endometrial cancer, atypical hyperplasia, previous diagnosis of CE, and received any antibiotic treatment in the period of 3 months before hysteroscopy were excluded. Study group included patients with unexplained infertility. The control group included those with no previous history of infertility, not taking hormone treatment in the past 3 months before hysteroscopy or having spontaneous pregnancy in the previous 3 years before the procedure. The diagnosis of CE was established after hematoxylin and eosin and CD 138 staining and was based on the presence of one or more plasma cells per 10 high-power fields. The primary outcome was the prevalence of CE compared between infertile and fertile patients. The secondary outcomes included clinical pregnancy rate (CPR), live birth rate (LBR) and miscarriage rate (MR) of infertile patients after CE treatment (Doxycycline 100 mg twice daily for 14 days) compared to infertile patients without CE. To determine factors significantly associated with CE we used multivariate logistical regression. A sample size of 100 in each group has 80% power of showing a 15% difference in primary outcome with an alpha of 5%. A total of 237 patients were included in the analysis. Demography, hysteroscopy cycle day, polyp location and diameter were similar between the groups. The prevalence of CE in group of patients with unexplained infertility (n=137) was significantly higher compared to the control group (n=140) [22.6% vs. 8.6%; P = 0.001]. Cumulative CPR, LBR and MR were similar between women with treated CE (n=31) and patients without CE (n=106). Multivariate logistical model showed that infertility diagnosis was significantly associated with the diagnosis of CE (OR 3.16; 95% CI 1.53 – 6.49). In women with endometrial polyps the prevalence of CE is higher in patients with unexplained infertility compared to patients without infertility history. The pregnancy outcome of infertile patients with CE treated with one course of Doxycycline was similar to those without CE.