Impact of Uterine Immune Profiling and Personalized Treatments in Patients Receiving a Single Blastocyst: a Matched Controlled Study

The PRECONCEPTIO software will be used to extract all the uterine immune profiles carried out between January 2020 and June 2023 for patients attending the two reproductive centres, Bluets and Diaconnesse.

In parallel, data will be extracted from the MEDIFIRST software selecting all patients who benefited from a single day 5 embryo transfer between January 2018 and March 2024.

The case group represents the selection of patients who had both uterine immune profiling prior to ET and Day 5 single embryo transfer within the nine months following uterine immune profiling.

Each patient in the treated group is matched to patients who had a single Day 5 ET without immune profiling in the nine months prior to ET.

Matching criteria will be maternal age (+/-1year) and, number of previous egg retrievals (including the ones without any transfer) and, number of previous ETs and technique used (IVF, ICSI, frozen embryo transfer) and degree of expansion of blastocoel (B1-B2/B3-B4/B5-B6) to reflect the quality of the embryo transferred The primary end-point is the live birth rate (LBR) following the Day 5 SET in the population who benefited from pre-SET immune profiling versus the LBR following the Day 5 SET in the pair- matched population who did not benefit from pre-SET uterine immune profiling Secondary end point are the clinical pregnancy rate and miscarriage rate per SET in the two paired populations

Impact of the uterine immune profiling on the live birth rate

• In function of the type of embryo transfer (fresh or freezed thawed)
• In function of the quality of the blastocyst transferred
• In function of the range of embryo transfer

For case: Uterine immune profiling followed by a Day-5 fresh SET or day-5 or Day-6 freeze-thawed SET within the nine months following the uterine immune profiling between January 2020 and June 2023.

Will be excluded patients with no SET day-5, with uterine immune profiling more than nine months before, or with no matching pair For control: Blastocyst SET without uterine immune profiling within the year prior the embryo transfer matched to the case group between January 2018 on June 2023

• maternal age (+/-1 year) and
• the past history of ART (same number of previous oocytes pick-up, same number of previous embryo transfer) and
• the same type of transfer (IVF, ICSI, frozen transfer) and
• the same category of expansion of the blastocoel (B1-B2/ B3-B4/ B5-B6).