Relationship between chronic endometritis and fallopian tube obstruction and its influence on pregnancy outcome after fallopian tubal recanalization

Background: Chronic endometritis (CE), frequently asymptomatic, is associated with female infertility. Fallopian tube obstruction (FTO) is also one of the factors contributing to female infertility. More than 90% of cases of proximal FTO can be successfully treated after fallopian tubal recanalization (FTR) and the spontaneous pregnancy rate of treated women after FTR is only about 30%. Potential factors affecting the success rate of FTR remain unclear. We speculate that CE may be one of the reasons affecting the recanalization of the fallopian tubes. Objectives: To identify the correlation between CE and FTO, as well as the influence of CE on pregnancy outcomes following FTR. Design: Retrospective observational study. Methods: We retrospectively analyzed 498 women of childbearing age who underwent laparoscopy and hysteroscopy surgery for infertility. Endometrial samples were collected during surgery for CD138 immunohistochemistry staining for the diagnosis of CE. Based on the results of the tubal patency test, they were divided into two groups: the fallopian tubal patency group and the proximal FTO group. The prevalence of CE was compared between these two groups. All women with FTO underwent FTR during the operation until successful treatment was achieved. Pregnancy outcomes were assessed after a 12-month follow-up period following the procedures. Logistic regression was used to analyze factors that might affect pregnancy after FTR. Results: The prevalence of CE in women with tubal obstruction was 30.5%, which was significantly higher than that in the fallopian tubal patency group (10.75%), p < 0.001. After FTR, the prevalence of CE in non-pregnant women was 40.18%, which was higher than that in pregnant women (40.18% vs 13.11%), and the difference was significant ( p < 0.001). Multiple regression analysis showed that CE was a significant risk factor for FTO (OR: 2.54, 95% CI: 1.368–4.717, p < 0.05). In addition, CE was identified as a risk factor for infertility after FTR (OR: 4.730, 95% CI: 2.012–11.122). Conclusion: The presence of CE seems to decrease the likelihood of achieving spontaneous pregnancy following FTR. This observation underscores the clinical importance of early detection and treatment of CE, emphasizing the necessity for immediate intervention to prevent potential fertility complications.