Assisted reproductive techniques (ART) have become the treatment of choice in many cases of male and female infertility. Despite technical advances in gamete handling and culture conditions, success rates after ART procedures are still unsatisfactory. Suboptimal oocyte and embryo quality is one of the many reasons contributing to poor pregnancy rates after in vitro fertilization (IVF)/intracytoplasmic sperm injection (ICSI). As our understanding of gamete and embryo metabolism has increased over recent years, we have come to the hypothesis that oxidative stress (OS) negatively impacts human embryos. OS has been implicated in arrested embryo development and poor quality embryos that develop in vitro. We reported that reactive oxygen species (ROS) are generated in culture media from developing embryos and are significantly high when there is low fertilization, low cleavage, low blastocyst development and increased fragmentation. This was specific in ICSI cycles and is explained by the potential antioxidant activity of cumulus cell mass around oocytes that are denuded during ICSI.
We measured levels of OS markers such as lipid peroxidation (LPO) and total antioxidant capacity (TAC) in the follicular fluid from women undergoing IVF treatment and found both markers correlated positively with pregnancy outcome. We demonstrated significantly increased levels of ROS and TAC in the follicular fluid of women undergoing IVF who became pregnant in contrast with those who did not. Follicular fluid ROS and lipid peroxidation levels may be viewed as markers for success with IVF.