Oxidative parameters of embryo culture media may predict treatment outcome in in vitro fertilization: a novel applicable tool for improving embryo selection

Objective: To examine whether the oxidative status of an individual embryo before transfer may predict chances of implantation.

Design: A prospective laboratory study.

Setting: An IVF unit in a university-affiliated hospital.

Patient(s): One hundred thirty-three women undergoing IVF-ET treatment cycles.

Intervention(s): Before ET, 10 μL of embryo culture medium was retrieved individually from each embryo and the oxidative status assessed by the thermochemiluminescence (TCL) analyzer.

Main outcome measure(s): The occurrence of pregnancy. Two parameters were recorded: the TCL amplitude after 50 seconds (H1) and the TCL ratio. These were compared with demographic, clinical, and laboratory parameters and treatment outcome. All data underwent statistical analysis.

Result(s): Altogether 284 embryos were transferred in 133 ET cycles. Forty-one pregnancies occurred (31%). For embryos transferred after 72 hours (77 transfers), the highest H1 levels in each group of transferred embryos correlated with the occurrence of pregnancy. The combination of maximal intracohort H1 level <210 counts per second with a TCL ratio of ≤ 80% had a positive predictive value of 70.6% for the occurrence of pregnancy.

Conclusion(s): The oxidative status of the early embryo in IVF is associated with the chances of implantation. Assessment of the oxidative status of embryos in culture media before transfer may serve as an applicable tool for improving embryo selection in light of the legal limitations of the number of transferred embryos allowed.