Background: Endometrial thickness has been identified as a prognostic factor for pregnancy rate for patients with female infertility. Thin endometrium is defined as <7 mm on the day of ovulation, or on the day of human chorionic gonadotrophin (HCG) injection in fresh in vitro fertilization (IVF) cycles, or the day to start progesterone in frozen-thaw embryo transfer cycles, as stated in the guideline of thin endometrium from the Canadin Fertility and Andrology Society and Chinese expert consensus from the Society of Reproductive Medicine, Chinese Medical Association. Many medicines are used for improving the endometrial thickness and embryo implantation rate of the patients with thin endometirum, but thin endometrium remains a major troublesome clinical problem with limited efficacy.Platelet-rich plasma (PRP), as a growing and robust therapeutic option in musculoskeletal medicine, is a preparation of autologous plasma with a high concentration of platelets, and the therapeutic mechanism is based on the capacity to supply supra physiologic amounts of essential growth factors to provide a regenerative stimulus for promoting repair in tissues with low healing potential. Some randomized controlled trials have reported the application of PRP for patients with thin endometrium with satisfactory effect. However, there is no systematic review on efficacy and safety of PRP as a treatment of thin endometrium.
Methods: The data and information will be retrieved from the databases of MEDLINE, Embase, Web of Science, Clinicaltrials.org., Cochrane Library, China Biology Medicine Database, Wan Fang Database, China National Knowledge Infrastructure Database, VIP Science Technology Periodical Database, and OpenGrey for gray literature. The randomized controlled clinical trials are going to be selected before December 20, 2019, in English or Chinese language, with the search terms including "thin endometrium,""platelet-rich plasma," "endometrial thickness," "hemorheology of endometrium," "pregnancy rate," and "adverse reactions." RevMan 5.3 will be used for systematic review and meta-analysis. This protocol will be reported according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses Protocols (PRISMA-P) statement, and the systematic review will be reported with the PRISMA statement.
Results and conclusion: The efficacy and safety of PRP for the treatment of thin endometrium will be evaluated, and the conclusion will be published to provide medical evidence for a better clinical decision of patients with thin endometirum.