Infertility affects approximately 10-15% of the population. The number of assisted reproduction procedures has increased by a factor of 3 to 5.3 worldwide over the last 20 years. Despite recent techniques, pregnancy rates seem to be limited to 35% by embryo transfer. Embryo implantation depends on two factors: the quality of the embryo and the endometrial receptivity. Although good quality embryos are transferred, implantation may not occur. Changes in the maternal cytokine profile at the time of implantation may result in poor implantation or early abortions. Consequently, a misdirection of the immunological profile could be responsible for repeated implantation failure (RIF). The definition of RIF is not consensual, but most commonly refers to 3 failures after good quality embryo transfer, and would affect between 5 and 10% of patients.

The possibility of defining a predictive immune profile for RIF from a peripheral blood sample is debated. However, after stimulation of immune cells in peripheral blood, patients with RIF show an excessive pro-inflammatory profile.

Our objective is to assess the activation of T cells and innate immune cells (via an anti-CD3 agonist and a TLR7-8 ligand, respectively) from a blood sample to predict implantation success after frozen embryo transfer. This functional test is easy to use and applicable in a clinical routine.

Inclusion Criteria:

• Adult women (aged 18 and above) treated in the Medically Assisted Procreation (MAP) center of the University Hospital of Nice, in the process of a frozen embryo transfer
• Social security affiliation
• Signed consent

Exclusion Criteria:

• Contra-indication to frozen embryo transfer
• Ongoing infection
• Patients under guardianship

Sharing data is not planned