Mitochondrial DNA content is not predictive of reproductive competence in euploid blastocysts

Abstract

RESEARCH QUESTION: Does mitochondrial DNA (mtDNA) copy number predict the reproductive potential of euploid human blastocysts? DESIGN: To investigate whether the amount of mtDNA in trophectoderm biopsies correlates with IVF outcome, euploid human blastocysts (n=615) used in single embryo transfer were analysed. Furthermore, to determine whether mtDNA content is predictive of reproductive outcome within a given cohort, paired sibling embryos (n=78) transferred in two consecutive cycles carried out in the same patient (in which one cycle failed to result in implantation and the other cycle resulted in sustained implantation) were studied. Targeted amplification followed by quantitative real-time polymerase chain reaction for two mitochondrial loci (16S and MajArc) relative to a multicopy nuclear genome locus (AluYb8) were carried out to determine relative mtDNA copy number. RESULTS: Sustained implantation was not associated with relative mtDNA copy number (P=0.78), and there was no threshold value above or below which ongoing implantation was more or less likely. No correlation was observed between maternal age and relative mtDNA copy number (P=0.39). In addition, no association was found between relative mtDNA levels of sibling embryos and ensuing implantation and delivery rates in women who underwent a successful single embryo transfer before or after a failed transfer using embryos derived from the same cohort of oocytes (P=0.70). CONCLUSIONS: In trophectoderm samples, mitochondrial DNA copy number analysis was not found to be predictive of euploid human embryo reproductive competence. These data do not support the use of mitochondrial DNA copy number in clinical decision making when selecting which embryo to transfer.