(HealthDay News) – Among women undergoing in vitro fertilization, embryos above a threshold amount of mitochondrial DNA (mtDNA) are less likely to implant, even if they are chromosomally normal, according to a study presented at the annual meeting of the American Society for Reproductive Medicine, held from Oct. 12–17 in Boston.

Elpida Fragouli, PhD, from Reprogenetics in Oxford, UK, and colleagues performed comprehensive cytogenetic analysis and quantified mtDNA in 219 blastocysts generated by 59 couples undergoing in vitro fertilization.

The researchers found a significant increase in the amount of mtDNA with increasing maternal age, particularly among those >38 years old. The amount of mtDNA was significantly higher in chromosomally abnormal embryos. Among chromosomally normal blastocysts transferred to the uterus, those able to establish viable clinical pregnancies contained significantly lower amounts of mtDNA.

“Of clinical importance, we were able to establish a threshold of mtDNA content above which the risk of implantation failure for a euploid embryo doubles,” Fragouli and colleagues conclude. “This data strongly suggests that mtDNA quantification represents a valuable new independent biomarker of embryo viability.”

The study was supported by institutional funding.

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