Chaotic Mosaicism in Human Preimplantation Embryos is Correlated with a Low Mitochondrial Membrane Potential

Objective: To determine the relationship between the intrinsic mitochondrial deltapsi of human embryos and the embryo karyotype.

Design: Analysis of mitochondrial deltapsi of living embryos followed by chromosomal enumeration with fluorescence in situ hybridization. A tertiary center for assisted reproduction technology.

Patient(s): Fifty-two patients attending the fertility center for assisted reproduction.

Intervention(s): Donated embryos were loaded with a mitochondrial deltapsi-sensitive fluorescence dye.

Main Outcome Measure(s): Mitochondrial deltapsi and embryo karyotype.

Result(s): An association was observed between low mitochondrial deltapsi and the detection of chaotic mosaicism. Analysis of oocytes suggested that this was due to the effect of low mitochondrial deltapsi on the morphology of the meiotic apparatus.

Conclusion(s): The data suggest that the intrinsic mitochondrial deltapsi of human oocytes programs the developmental fate of embryos through an effect on the ability of oocytes to form a normal meiotic apparatus and not through nondisjunction.