Metabolism and developmental competence of the preimplantation embryo.

In vitro fertilisation (IVF) has permitted many thousands of couples to conceive world-wide yet is limited by low success rates and a confounding high multiple birth rate due to the transfer of more than one embryo. These problems could be overcome if single embryos of known developmental competence could be selected for replacement. It is clear that current embryo selection methods, which rely on morphological appearance alone, are poor predictors of viability. Metabolism is intrinsic to embryo health and much research has concentrated on developing a non-invasive metabolic marker of developmental competence.