Using endometrial immune profiling in young IVF patients: implantation rates improved for morphologically sub-optimal embryos

Introduction: A balanced endometrial immune profile is considered to be the ideal environment for a successful implantation, as opposed to endometrial immune dysregulation. However, the embryo quality may be the pivotal 'immune' factor compared to the uterine immune environment. Study method: After providing informed consent, young infertile patients involved in ART underwent an analysis of their endometrial immune profile before their embryo transfer (ET). Each ET was classified as a Top transfer if the used embryos were of Top morphology; all other transfers were classified as non-Top. The live birth rate (LBR) after ET was compared between patients with a balanced endometrial immune profile and patients with a dysregulated endometrial immune profile, with no intervention to regulate the endometrial environment (conventional care). Results: Overall, the LBR did not differ significantly between patients with balanced and dysregulated endometrial profile receiving conventional care (39.5% vs 29.7%; OR: 1.55 [0.66-2.72]). However, among patients with a non-Top transfer, the LBR was higher in the balanced group (38.4% vs 21.2%; OR: 2.11 [1.02-4.37]). In contrast, no difference was observed in the case of a Top transfer (46.3% vs 45.8%; OR: 0.99 [0.38-2,55]). Conclusion: These preliminary results suggest that a balanced endometrial immune environment may favour the implantation in patients using morphologically suboptimal embryos. In contrast, an endometrial immune dysregulation negatively impacts the implantation of morphologically suboptimal embryos. Trial registration: NCT02262117. Trial registration date: October, 7th, 2014. Date of the first patient’s enrolment: October, 30th, 2015.