Effectiveness of endometrial scratching in infertility treatment with assisted reproductive technologies

Abstract

Embryo implantation is a key factor limiting the effectiveness of assisted reproductive technologies, and depends on the quality of the blastocyst and the susceptibility of the endometrium. Various methods of treatment aimed at improving the receptivity of the uterine mucosa, including endometrial scratching, have been proposed. At the same time, the main mechanisms underlying this intervention remain unclear. Moreover, the optimal duration of exposure to the uterine mucosa and the groups of patients in which it can have a positive effect have not been determined. The study aims to investigate the main mechanisms and evaluate the effectiveness of local endometrial damage performed at various times before embryo transfer in the program of assisted reproductive technologies in women with and without a history of implantation failures based on the analysis of scientific literature. Clinical studies, systematic reviews and meta-analyses were studied in PubMed, Embase, Cochrane Library, Web of Science databases, Elsevier, Springer, Wiley publishers, on eLibrary, Research Gate platforms, in open sources of the scientific and educational segment of the Internet. The literature search was conducted by keywords: endometrial scratching, local endometrial damage, implantation failures, endometrial receptivity, assisted reproductive technologies, infertility. The search depth is 20 years. The main mechanisms of the effect of scratching on increasing endometrial receptivity include decidualization, the development of a local inflammatory reaction, as well as improved synchronization between the uterine mucosa and the transferred embryo by preventing premature maturation of the endometrium. Studies that showed a positive effect of local damage to the uterine mucosa were mainly conducted in patients with repeated implantation failures and with intervention in the luteal phase of the cycle preceding stimulation. At the same time, the work performed in a non-selective population of women and non-standardized by exposure time, in most cases, did not reveal the advantages of endometrial scratching. In this regard, additional qualitative randomized controlled trials with a large sample size and a clear identification of groups of patients for whom this intervention may benefit are required.