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 1163937 (n = 8, from three patients); grade 8B embryos, at 939345 (n = 5, from two patients); grade 8C(+) embryos, at 637872 (n = 12, from 5 patients); and grade 8C(+) embryos derived from 3PN zygotes, at 300429 (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.
