Chronic endometritis and infertility — in vitro fertilization outcomes: systematic review and meta-analysis

Abstract

Background. The relevance of the problem is related to the high prevalence of chronic endometritis (CE); its role in female infertility, implantation failures during assisted reproductive technology procedures, and recurrent miscarriage; as well as the lack of a unified strategy in the diagnosis and treatment of this pathology. The present systematic review with a meta-analysis focuses on evaluating the impact of CE and its therapy on the outcome of in vitro fertilization. In addition, the effect of CE of various severity on the outcomes of assisted reproductive technologies is analyzed. Objective. To analyze the effect of CE of varying severity and its treatment on the outcomes of in vitro fertilization. Methods. Using PubMed, Medline, Scopus, Embase, ELibrary, Cochrane Central Register of Controlled Trials (CENTRAL), WHO International Clinical Trials Registry, and Russian Science Citation Index, a systematic search was conducted for articles published over the past 12 years that met the following criteria: randomized controlled trial examining the effect of CE of varying severity on fertility and ways to treat it. The following indicators were calculated: ongoing pregnancy/live birth, clinical pregnancy, and miscarriage rates. A total of 4145 patients (from ten studies) were included. A meta-analysis was performed using Stata 11.0 software (The Cochrane Collaboration, Oxford, UK). The heterogeneity was considered low at I2 <30%, moderate at 30–50%, and high at >50%. Results. Women with CE exhibited lower ongoing pregnancy/live birth (OR 1.97; p = 0.02) and clinical pregnancy rates (OR 2.28; p = 0.002) as compared to women without it. CE treatment increased the ongoing pregnancy/live birth (OR 5.33; p < 0.0001) and clinical pregnancy rates (OR 3.64; p = 0.0001). In vitro fertilization outcomes were comparable in women treated for CE and women without CE (ongoing pregnancy/live birth rate, clinical pregnancy rate, and miscarriage rate: p = ns). Women with severe CE exhibited lower ongoing pregnancy/live birth (OR 0.43; p = 0.003) and clinical pregnancy rates (OR 0.40; p = 0.0007). Mild CE showed no significant effect on in vitro fertilization outcomes (ongoing pregnancy/ live birth rate, clinical pregnancy rate, and miscarriage rate: p = ns). Conclusion. The conducted meta-analysis showed that CE significantly reduces the ongoing pregnancy/live birth and clinical pregnancy rates in infertile women undergoing in vitro fertilization. Noteworthy is that antimicrobial therapy in such patients improves the results of assisted reproductive technologies, which are comparable to those of patients without CE. The negative impact of this pathology on the implantation capacity of the endometrium is most often observed in the severe form, while its mild form has virtually no effect on the in vitro fertilization outcome.