Comparison of mitochondrial DNA contents in human embryos with good or poor morphology at the 8-cell stage

Objective: To quantify the mitochondrial DNA contents in human embryos with good or poor quality at the 8-cell stage. Design: Prospective study. Setting: Private infertility clinic. Patient(s): Five women aged 24 to 34 years. Intervention(s): Embryos obtained in standard superovulation and embryo culture procedures. Main outcome measure(s): Mitochondrial DNA (mtDNA) copy numbers in human embryos at cleavage stage were quantified by real-time polymerase chain reaction, in an effort to correlate with morphology. Result(s): The grade 8A embryos contained a mean mtDNA copy number at 1,163,937 (n = 8, from three patients); grade 8B embryos, at 939,345 (n = 5, from two patients); grade 8C+ embryos, at 637,872 (n = 12, from 5 patients); and grade 8C+ embryos derived from 3PN zygotes, at 300,429 (n = 3, from a single patient). Conclusion(s): Great variations were found among blastomeres from a single embryo and among embryos from a single patient. The native variations of mtDNA copy number may affect developmental ability irrespective of morphology.