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

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.