Patients with recurrent implantation failure are among the most difficult patients to treat, with no proven standard treatment. Platelet rich plasma stimulates cellular processes involved in endometrial regeneration, and in a small case series has shown efficacy for this patient population. We hope to conduct a randomized controlled pilot study to determine whether PRP is indeed an effective treatment for recurrent implantation failure.

Patients considered to have recurrent implantation failure will undergo randomization to receive intrauterine infusions of platelet rich plasma or a placebo of embryo culture media prior to their embryo transfer. All patients will undergo a blood draw to obtain 60ml of blood from which 0.5ml of platelet rich plasma will be obtained. Those randomized to receive the platelet rich plasma will have platelet rich plasma placed into the uterine cavity at least 48 hours prior to the embryo transfer, while those randomized to receive placebo will have embryo culture media placed into the uterine cavity at the same point in time. Those randomized to the placebo group will have the opportunity to be placed into the treatment group if no pregnancy was attained. Transfer outcomes including implantation rate, pregnancy rate, and live birth rate, will be recorded.

Inclusion Criteria:

• All women who have undergone 3 or more embryo (blastocyst stage) transfers without establishing a clinical pregnancy or 2 or more euploid embryo transfers without establishing a clinical pregnancy, aged 18 - 45, with a normal uterine cavity established within 12 months by hysteroscopy or saline infusion sonogram, planning in vitro fertilization with an embryo transfer at Stanford Fertility and Reproductive Health. The planned transfer must consist of any of the following: a PGS proven euploid embryo, a good quality blastocyst from a patient younger than 37, or a donor oocyte blastocyst.

Exclusion Criteria:

• Abnormal uterine cavity, planning in vitro fertilization with use of a gestational carrier. patients enrolled in other experimental interventions for RIF will be excluded. Patients with only poor quality or cleavage stage embryos.

Patients will be blinded to the treatment they received, but providers and investigators will be aware.