The value of endometrial scratch injury in infertile women trying to conceive through non-in vitro fertilization cycles: A systematic review and meta-analysis.

To assess the effects of endometrial scratch injury (ESI) in infertile couples seeking fertility through non-in vitro fertilization (IVF) cycles. We conducted a comprehensive search of MEDLINE, EMBASE, Web of Science, Scopus, the Cochrane Library, and Google Scholar from their inception through August 2023. The search terms included 'endometrial scratch,' 'infertility,' 'implantation,' 'intrauterine insemination (IUI),' and their corresponding MeSH terms. We included all published and unpublished randomized controlled trials involving ESI in women undergoing either natural or IUI cycles. The ESIs varied in severity and were performed during either the follicular or luteal phase of the same or preceding cycle. Our review encompassed 32 studies, totaling 5,897 participants. Of these, seven studies with 1,094 participants assessed ESI in natural cycles, while 25 studies with 4,803 participants evaluated it in IUI cycles. The data extracted included trial location, number of participants, inclusion and exclusion criteria for participants, details of the ESI, and outcome parameters (trial registration: CRD42023434127). ESI significantly increased the clinical pregnancy rate (odds ratio [OR], 2.06; 95% confidence interval [CI], 1.72 to 2.47; p<0.001), ongoing pregnancy/live birth rate (OR, 1.68; 95% CI, 1.32 to 2.13; p<0.001), and chemical pregnancy rate (OR, 2.32; 95% CI, 1.79 to 3.00; p<0.001). However, it had no significant effect on the rates of multiple pregnancy, miscarriage, and ectopic pregnancy (p>0.05). ESI improved the clinical pregnancy rate, ongoing pregnancy/live birth rate, and chemical pregnancy rate in both natural and IUI cycles.