Oxygen consumption is a quality marker for human oocyte competence conditioned by ovarian stimulation regimens

Objective: To evaluate the effect of different ovarian stimulation protocols on oocyte respiration and to investigate the relationship between oocyte oxygen consumption and reproductive outcome. Design: Prospective observational cohort study. Setting: Infertility clinic in a university hospital. Patient(s): A total of 349 oocytes from 56 IVF treatment cycles in our oocyte donation program. Intervention(s): None. Main Outcome Measure(s): Average oocyte oxygen consumption rate in fmol/s. We correlated oxygen consumption values with ovarian stimulation features, fertilization, embryo quality on days 2 and 3, and implantation. Result(s): Differences in the measured oxygen consumption rates were found depending on which type of gonadotropins were used in the stimulation protocol. Higher consumption rates were found for oocytes that underwent normal fertilization compared with rates from nonfertilized or abnormal oocytes (odds ratio = 1.340; 95% confidence intervals = 1.037-1.732). Furthermore, higher oxygen consumption was observed for those oocytes which generated embryos that implanted compared with those that did not implant (6.21 +/- 0.849 fmol/s vs. 5.23 +/- 0.345 fmol/s. Conclusion(s): Measurement of oxygen consumption rates for individual oocytes before fertilization provides a noninvasive marker of oocyte quality and hence a quantitative assessment of the reproductive potential for the oocyte. (Fertil Steril (R) 2011;96:618-23. (C)2011 by American Society for Reproductive Medicine.)