P–345 Reproductive outcome after treatment of chronic endometritis in patients with recurrent implantation failure

Study question Does the treatment of chronic endometritis (CE) improve reproductive outcome in patients with recurrent implantation failure (RIF)? Summary answer Treatment and resolution of CE seem to improve pregnancy rates in patients with implantation failure and CE. What is known already Over the last 10 years, the interest in the study of CE has increased given its important association with reproductive failure. The main cause of CE is an infection of the endometrial cavity caused by common microorganisms. Therefore, the recommended treatment is antibiotic therapy. Numerous studies demonstrate an improvement in reproductive outcome in patients with treated and resolved CE. The objectives of this study are to evaluate the resolution rate of CE after antibiotic treatment in patients with implantation failure diagnosed with CE and to analyse their reproductive outcome after treatment. Study design, size, duration In this prospective case series, all patients with RIF who underwent diagnostic hysteroscopy, IHC analysis with CD138 of an endometrial biopsy and microbiological analysis of an endometrial sample between October 2018 and February 2019 were included. Participants/materials, setting, methods Hysteroscopic findings suggestive of CE were collected and endometrial biopsies were taken for pathological study with CD138 and microbiological assessment. Likewise, treated endometrial samples and the results of hysteroscopy or control biopsies after treatment were collected. The data of embryo transfers post-treatment were also included in our study. Main results and the role of chance 30 patients with implantation failure were included. 15 patients (50%) were diagnosed with CE using any of the aforementioned diagnostic methods. All diagnosed patients were treated with antibiotic therapy: positive microbiological samples (9) were treated according to our antibiogram whereas those samples who were negative but were confirmed to have CE by hysteroscopy or pathological assessment (6) were treated with doxycycline. In all cases, CE resolved after treatment, except only one patient who required a second course of antibiotics to acquire a negative result. Ten patients underwent an embryo transfer after resolution of CE, resulting in 60% of ongoing pregnancies. Limitations, reasons for caution Although our results are encouraging and in accordance with other studies, we are aware that this is an observational non-randomised study with a limited number of patients. Wider implications of the findings: It seems that the treatment of CE, following its diagnosis using the aforementioned methods, can improve pregnancy rates in patients with RIF and CE. Therefore, it is likely recommendable to study CE using these three tests. Trial registration number Not applicable