Endometrial thickness after platelet-rich plasma infusion is associated with live birth in women with thin endometrium undergoing frozen embryo transfer: a single-arm retrospective cohort study

Abstract Background A thin endometrium is closely associated with adverse reproductive outcomes during the implantation window. In the field of regenerative medicine, platelet-rich plasma (PRP) is a highly promising therapeutic option; however, evidence supporting its efficacy in patients with thin endometrium remains limited. The present study evaluated how intrauterine PRP infusion influences endometrial thickness (EMT) and reproductive outcomes in frozen embryo transfer (FET) cycles, while also identifying determinants of live birth rates. Methods We performed a retrospective single-arm study with self-controlled analysis of 139 FET cycles in patients with thin endometrium. All participants received an intrauterine PRP infusion at a platelet concentration of approximately 1000–1200 × 10⁹/L. Changes in EMT from the cycle before PRP therapy to the treatment cycle were evaluated. FET outcomes were statistically analyzed, followed by multivariate regression to identify the factors affecting PRP-FET clinical outcomes. Results EMT significantly improved following PRP infusion, increasing from a mean of 5.6 ± 1.0 mm at the previous canceled cycle to 7.0 ± 1.0 mm ( P < 0.01). The biochemical pregnancy, clinical pregnancy, and live birth rates were 52.5% (73/139), 45.3% (63/139), and 34.5% (48/139), respectively. Multivariate analysis revealed a strong link between EMT after PRP and live births ( P = 0.02). However, there was no significant association between the number of PRP infusions and the live birth rate ( P = 0.946). Conclusions PRP infusion was associated with increased endometrial thickness and favorable pregnancy outcomes in patients with thin endometrium. EMT after PRP was significantly associated with live birth, whereas infusion frequency was not related to live-birth outcomes. However, the absence of a control group limits the strength of these conclusions, and well-designed randomized controlled trials are needed to validate the efficacy of PRP.