What is the evidence for PRP in recurrent implantation failure?

Platelet-rich plasma for endometrial application remains experimental. It should not be offered as an established treatment. The rationale — that concentrated growth factors promote endometrial proliferation and receptivity — is biologically coherent. What is lacking is evidence that it improves live birth rates. The evidence base consists largely of small studies, many without randomisation or adequate control, with heterogeneous preparation protocols. PRP is not a standardised product: platelet concentration, activation method, volume and timing differ between studies and between clinics, so results are not readily comparable and a positive finding in one protocol does not transfer to another. Reported outcomes are frequently surrogate — endometrial thickness rather than live birth. Thickness is a weak predictor of outcome, so improvement in it does not establish clinical benefit. The position to take with patients: PRP is unproven, not merely under-studied. It is offered commercially and often at significant cost, and the marketing typically outpaces the evidence considerably. Where a patient wishes to pursue it, that should follow an explicit conversation that benefit has not been demonstrated, ideally within a trial. Reviewer: check whether any RCT with live birth as primary endpoint has reported since this was written.