Study deferred/stopped by initiator before any study recruitment was initiated.

Platelet Rich Plasma (PRP), a rich source of important growth factors, has been shown to significantly affect the body's ability to heal and regenerate tissues. It is an affordable, accessible treatment with little risk of side effects that is being utilized in many areas of regenerative and cosmetic medicine. PRP is also relatively easy to prepare with supplies on hand in most IVF clinics. Specifically relating to reproductive function, PRP has been demonstrated to increase cellular proliferation and decrease fibrosis in damaged rat endometrium. It is hypothesized that infusing the uterus with Platelet Rich Plasma at measured intervals prior to embryo transfer will increase concentrations of implantation-promoting cytokines while reducing concentrations of inflammatory cytokines during the window of implantation.

1. Platelet Rich Plasma (PRP), a rich source of important growth factors, has been shown to significantly affect the body's ability to heal and regenerate tissues.7 It is an affordable, accessible treatment with little risk of side effects that is being utilized in many areas of regenerative and cosmetic medicine. PRP is also relatively easy to prepare with supplies on hand in most IVF clinics. PRP has shown great promise in veterinary medicine to regenerate tissues and reduce endometrial inflammation.8 Specifically relating to reproductive function, PRP has been demonstrated to increase cellular proliferation and decrease fibrosis in damaged rat endometrium.6 Endometritis, which is characterized by an increase in inflammatory cells, erosion of the endometrial epithelial layer as well as endometrial edema has been a large cause of infertility in cattle and therefore revenue loss in the cattle industry. A recent study applying uterine infusion of PRP as the intervention demonstrated decreased markers for inflammation in cattle in vivo and as well as decreased inflammatory markers in in vitro cultured endometrial cells exposed to PRP.6 A similar in vitro study was conducted on horses; the authors noticed a decrease in clinical uterine infections in mares along with an increased embryo recovery rate.31 Chronic endometritis is hypothesized to be one of the potential factors involved in recurrent implantation failure in women.32 Using these previous studies in veterinary medicine as a model for potential benefit in human patients, it would be prudent to explore the mechanism of PRP action in humans. It is hypothesized that infusing the uterus with Platelet Rich Plasma at measured intervals prior to embryo transfer will increase concentrations of implantation-promoting cytokines while reducing concentrations of inflammatory cytokines during the window of implantation. TGF-b, IL-6 and LIF are known to be promoters of implantation, while TNF-a and IL-4 are pro-inflammatory factors and can inhibit implantation.

Inclusion Criteria:

• Patient at REI clinic population
• Ages 23 to 45
• Undergo frozen embryo transfers with clinic standard medicated protocols
• Transferring one or two embryos on day 5 or 6 of development

Exclusion Criteria:

• BMI >32
• Low level or high-level mosaic
• Aneuploid embryos only will be excluded
• Desiring day 3 or fresh embryo

Patients assigned female at birth, who are capable of becoming pregnant.

2. It is not possible to blind clinical staff for the procedure. It is not necessary for the integrity of the study to blind participants as we are assessing their pregnancy outcomes. Regardless of which group they are assigned, participants will partake in routine prenatal care, as well as two additional study visits. They will know which group they have been assigned at the time of the procedure based on if they receive the treatment prior to implantation or not.