P-387 Autologous Platelet-Rich Plasma (PRP) intrauterine infusion before embryo transfer could improve the treatment outcomes, especially for transferring euploid blastocysts, in recurrent implantation failure patients

Abstract Study question Is the intrauterine infusion of autologous PRP prior to embryo transfer, especially euploid blastocyst transfer, effective in solving recurrent implantation failure? Summary answer Autologous PRP intrauterine infusion before embryo transfer (ET), especially before transferring euploid blastocysts, could improve the treatment outcomes in RIF patients. What is known already Firstly, autologous PRP intrauterine infusion has been proposed to improve the outcomes of ET in patients having thin endometrium or a history of RIF. Hypothetically, growth factors and cytokines in PRP assist in preparing endometrium surface as well as conducting critical early molecular signaling pathways between the embryos and the uterus. We have developed and optimized a specific PRP infusion protocol for RIF (presented at ESHRE 2021, P-428). Secondly, various reports have suggested that transferring euploid blastocysts have better results than unscreened ones. Here we evaluate the effects of PRP infusion, together with transferring euploid blastocysts in RIF treatment. Study design, size, duration From 11/2020 - 07/2021, all patients who had one PRP infusion before ET were recorded (n = 130). RIF patients were classified as follows: group A (unscreened blastocysts, n = 51 patients) included having at least two ET failures (beta-hCG < 5 IU/L). The embryos in this group did not undergo preimplantation genetic testing for aneuploidy (PGT-A). Group B (euploid blastocysts, n = 50 patients) were cases having at least one ET failure using euploid blastocysts previously screened by PGT-A. Participants/materials, setting, methods Endometrium preparation was followed hormone replacement protocol using E2 and P4 with autologous PRP infusion 48 hours before ET. All ETs in this study were frozen blastocyst ones. Apart from groups A and B, a small group of patients (n = 29) might not have previous unsuccessful ET but had relatively thin endometrium (< 9 mm), hence requiring PRP treatment. Beta-hCG, yolk sac and clinical pregnancy outcomes were recorded. A Chi-square test was applied. Main results and the role of chance 76/130 patients in this study had beta-hCG positive (58.5%). Here, we focused on RIF, therefore only data of groups A and B were analyzed (n = 29 cases without previous ET failures excluded). In group A (n = 51), 26 cases had beta-hCG positive (51%); 21 cases (41.2%) had yolk sac and then clinical pregnancy; five cases had only biochemical pregnancy. In group B (n = 50), 26 cases had beta-hCG positive (52%), 23 cases had gestational sac and then clinical pregnancy (46%); three cases had biochemical pregnancy. PRP infusion had positive impacts on implantation (all groups had >50% beta-hCG positive). The rates of beta-hCG positive in groups A and B were both lower than this rate in total patients suggesting that relatively thin endometrium (< 9 mm) may not critically require PRP infusion. The beta-hCG rates of groups A and B were statistically indifferent (p > 0.05). However, group B had higher average age than group A (37.7 ± 6.5 vs 33.06 ± 4.92), and had several poorer prognosis patients such as patients having low AMH, endometriosis or hydrometrocolpos. This result implied that PGT-A could help older and poorer prognosis RIF patients equal treatment outcomes with the younger and better prognosis RIF patients. Limitations, reasons for caution There were fewer biochemical pregnancy events in group B than group A (three vs. five), however, the study had a small sample size requiring ongoing enrolment to confirm this conclusion. This is impossible for this type of intervention study to have control (a group without PRP infusion). Wider implications of the findings On the side of the endometrium, PRP intrauterine infusion showed positive effects in assisting RIF patients to have implantation. On the embryo's side, embryo selection, especially PGT-A for euploid ones, could critically contribute to successful implantation and pregnancy. Trial registration number Not applicable