Intrauterine infusion and sub-endometrial injection of autologous platelet-rich plasma for thin endometrium: A systematic review and single-arm meta-analysis.

To evaluate the efficacy and safety of autologous platelet-rich plasma (PRP), administered via intrauterine infusion or subendometrial injection, for improving endometrial thickness (EMT) and pregnancy outcomes in women with thin endometrium undergoing frozen-thawed embryo transfer (FET) cycles. A comprehensive literature search was conducted across PubMed, Embase, Web of Science, and the Cochrane Library in accordance with preferred reporting items for systematic reviews and meta-analyses recommendations. Eligible studies investigating PRP treatment for thin endometrium in FET cycles were included. Methodological quality was assessed using the Methodological Index for Non-Randomized Studies. Pooled mean differences (MD) for EMT and aggregated proportions for pregnancy outcomes were calculated using R software. Fourteen studies involving a total of 523 patients were analyzed. PRP administration was associated with a significant increase in EMT [MD=1.61 mm, 95% confidence interval (CI): 1.21-2.01, p<0.05]. The pooled clinical pregnancy rate following PRP treatment was 41.5% (95% CI: 29.6-53.9%). Corresponding rates for ongoing pregnancy, implantation, and miscarriage were 27.3% (95% CI: 19.7-35.0%), 22.9% (95% CI: 8.5-37.2%), and 5.3% (95% CI: 2.3-8.2%), respectively. Subgroup analyses suggested that heterogeneity was partly attributable to differences in study design and PRP administration route. Autologous PRP may be a safe and potentially effective adjunct to enhance endometrial receptivity and reproductive outcomes in women with thin endometrium. Although current evidence from single-arm studies provides a useful clinical reference, well-designed, large-scale randomized controlled trials are still needed to validate these findings.