JBRA Assisted Reproduction 2025;29(Suppl.2 SBRA 2025):82
Poster Presentation
29^th Annual Congress of the SBRA. São Paulo/SP - Brazil, 2025
doi: 10.5935/1518-0557.20263661

P-70. Effect of PRP on Thin Endometrium in IVF Cycles with Fresh or Frozen-Thawed Embryo Transfer

Rodopiano Souza Florêncio¹, Mirian Rodrigues Borges¹

¹ Humana Medicina Reprodutiva - Goiânia - GO - Brasil

Objective: The success of IVF/ICSI cycles depends on multiple factors, with embryo quality and endometrial receptivity being key determinants. Endometrial thickness, measured by transvaginal ultrasound, is widely used as an indirect marker of receptivity. Thicknesses below 7 mm are associated with lower clinical pregnancy (CP) and live birth (LB) rates. Studies indicate ideal cut-off points of 8 mm for fresh transfers and 7 mm for frozen embryo transfers (FET). Conditions such as synechiae, uterine malformations, adenomyosis, submucosal fibroids, polyps >1 cm, and alterations in endometrial receptors can result in a thin endometrium, often refractory to conventional therapies, including sildenafil, G-CSF, and acetylsalicylic acid. Platelet-rich plasma (PRP), an autologous concentrate obtained from the patient's blood, contains growth factors and pro-angiogenic cytokines capable of stimulating tissue regeneration. Its use in assisted reproduction was inspired by positive results in other areas of regenerative medicine and in animal models, in which it promoted cell proliferation, angiogenesis, and reduced fibrosis. To review the literature from the past 10 years on the use of PRP for the treatment of thin endometrium in assisted reproduction cycles.
Methods: A review was conducted in the PubMed and Scopus databases (2015–2025) using descriptors related to PRP and thin endometrium. Prospective and retrospective studies, narrative reviews, and meta-analyses were included. Duplicate papers, those with other indications, or unpublished studies were excluded, totaling 66 publications.
Results: The association between endometrial thickness <7 mm and reduced CP and LB rates is consistent. PRP has been administered mainly by intrauterine infusion (0.5–1 ml) or by subendometrial injection guided by ultrasound or hysteroscopy, in one to three applications per cycle. In animal models, activated PRP accelerated endometrial regeneration and reduced fibrosis. In humans, Chang et al. (2015) reported five cases with increased endometrial thickness and 100% CP after infusion. Eftekhar et al. (2018) demonstrated a significant benefit after the second infusion in patients with endometrium <7 mm. Recent studies, such as Aghajanova et al. (2024), reported LB rates of 56%, and Castels et al. (2025) suggested a persistent effect for up to three cycles. PRP stimulates endometrial mesenchymal stem cells, increasing proliferation, migration, and cell adhesion. Activated preparations have platelet concentrations up to four times higher than plasma and high levels of PDGF, TGF, and VEGF. Comparisons between infusion and subendometrial injection show both to be effective, although some authors report greater thickness and CP with injection (Zaha et al., 2023). Meta-analyses confirm the benefit of PRP, with increases in thickness (RR up to 3.46), CP (RR up to 2.51), and LB (RR up to 7.03). A Cochrane review (Vaidakis et al., 2024) found ORs of 2.22 for CP and 2.38 for LB.
Conclusion: PRP, administered by infusion or subendometrial injection, is a promising therapy for thin endometrium, with consistent evidence of increased thickness and improved reproductive outcomes. Despite positive results, the heterogeneity of protocols and the limited number of randomized clinical trials underscore the need for standardized studies to define the optimal route, dose, and timing of administration.