Low oxygen concentrations for embryo culture in assisted reproductive technologies

Abstract

Background During IVF and ICSI procedures, human preimplantation embryos are cultured in the laboratory. While some laboratories culture in an atmospheric oxygen concentration (20%), others use a lower concentration (5%) as this resembles more closely the oxygen concentration observed in the oviduct and the uterus. Animal studies have shown that atmospheric oxygen concentrations could have a negative impact on embryo quality via reactive oxygen species causing oxidative stress. In humans, it is currently unknown which oxygen concentration provides the best success rates of IVF/ ICSI procedures resulting in the highest birth rate of healthy newborns. This is a summary of a meta-analysis recently published in the Cochrane Library (Bontekoe et al., 2012) evaluating whether embryo culture at low oxygen concentrations improves the treatment outcome when compared with embryo culture at atmospheric oxygen concentrations.