LAUSR

Abstract Background: Thin endometrium, defined as <7 mm of the endometrial thickness around ovulation period, had been identified as a negative factor on pregnancy rate of infertile women. It was considered to be the toughest part in treatment of infertility, because there was a lack of significant effect, although many drugs had been already used. Icariin was one of the major bioactive pharmaceutical constituent extracted from the Chinese herb “Ying Yang Huo,” in the genus of Epimedium, and some randomized controlled trials reported its application for thin endometrium. There is no systematic review focusing on the effective of icariin in treating infertile women with thin endometrium, so our review aims to explore it. Methods: The bibliographic database and electronic library will be systematically searched online, such as MEDLINE, EMBASE, Web of Science, Clinicaltrails.org., China National Knowledge Infrastructure Database (CNKI), Wan fang Database, China Biology Medicine Database (CBM), VIP Science Technology Periodical Database, and Cochrane Library. And the reference listed for potential literatures of included studies will be scanned additionally. Related randomized controlled trials (RCTs) will be collected and selected before January 4, 2020. Trials will be screened by independent reviewers, and the literature will be search in English or Chinese, with the search terms as “Icariin,” “Epimedium,” “infertile women,” “female infertility,” “endometrium,” “pregnancy rate.” The software for Systematic review and Meta-analysis is RevMan 5.3. The protocol and the systematic review will be reported according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses Protocols (PRISMA-P) statement. Result and conclusion: The efficacy of icariin to treat thin endometrium will be evaluated, and the conclusion will be published to help clinicians determine treatment strategy for infertile women with thin endometirum by providing medical evidence. Registration information: PROSPERO CRD42019148977.