Impact d’une concentration dynamique en oxygène pendant l’étape de culture embryonnaire en fécondation in vitro sur le développement embryonnaire préimplantatoire humain et le taux de naissances vivantes

In in vitro fertilization (IVF), human embryos are usually cultured under 5% oxygen during preimplantation development. Recent data suggest that a dynamic (5%-2%) oxygen strategy during human preimplantation embryo culture could improve IVF outcomes. A retrospective cohort study was carried out at the Montpellier University Hospital between june 2014 and march 2019. A total of 120 couples who had benefited from one IVF cycle under monophasic (5%) oxygen strategy and one subsequent IVF cycle under dynamic (5%-2%) oxygen strategy was enrolled. Our results showed that a dynamic (5%-2%) oxygen strategy was significantly associated with improved IVF outcomes, with higher total (54.8% (297/542) vs. 44.4% (230/518), p = 0.0007) and usable (32.8% (178/542) vs. 21.8% (113/518), p < 0.0001) blastulation rates as well as increased cumulative implantation (37.3 ± 43.0% vs.13.5 ± 23.7%, p = 0.003), clinical pregnancy (36.7 ± 43.5% vs. 15.0 ± 31.0%, p = 0.004) and live birth (31.1 ± 42.1% vs. 7.4 ± 16.9%, p = 0.002) rates compared to monophasic (5%) oxygen strategy. The implementation of dynamic (5%-2%) oxygen strategy during preimplantation embryo culture in IVF centres worldwide could increase the “take home baby rate”, improving the cost-effectiveness of IVF and the management of infertile couples. The characterization of molecular mechanisms involved in the improvement of embryo implantation potential under dynamic (5%-2%) oxygen strategy is under investigation in the laboratory. Further randomised control trials are warranted to infirm or confirm these interesting data.