Mitochondria DNA deletion and copy numbers of cumulus cells associated with in vitro fertilization outcomes.

ABSTRACT

OBJECTIVE: Mitochondria are important organelles in cell biology. We aimed to study the effects of mitochondrial DNA variations in cumulus cells (CCs) upon in vitro fertilization and embryo transfer (IVF-ET) outcomes. STUDY DESIGN: A total of 51 women undergoing IVF-ET were recruited for the study. The CCs were collected during oocyte retrievals. Mitochondria DNA 4977-bp deletion (dmtDNA-delta5Kb) and copy numbers (MCN) of CCs were analyzed by polymerase chain reaction. The relationships of dmtDNA-delta5Kb and MCN with patients' age, embryo qualities and pregnancy rates (PRs) were detected and compared. RESULTS: PRs were positively correlated with younger age, better transferred embryo qualities and lower dmtDNA-delta5Kb ratios in CCs. The dmtDNA-delta5Kb status was positively associated with older age and higher MCN but was not associated with embryo morphologic scoring. The dmtDNA-delta5Kb ratios of transferred embryos in pregnancy and nonpregnancy groups were 0% and 10.4%, respectively. The dmtDNA-delta5Kb in > or = 34-year-old and <34-year-old groups were 6.9% and 3.2%, respectively. CONCLUSION: The dmtDNA-delta5Kb and MCN statuses of CCs are negatively associated with PRs, which might be potential tools for oocyte evaluation and embryo selections during IVF-ET.