Résumé
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.