No association of mitochondrial DNA levels in trophectodermal cells with the developmental competence of the blastocyst and pregnancy outcomes

Abstract

17Study question 18 Can mitochondrial DNA (mtDNA) levels in trophectodermal cells of the blastocyst predict the 19 blastocyst quality, ploidy status, implantation rate and clinical outcomes? 20 Summary answer 21 mtDNA levels in trophectodermal cells of the blastocyst do not associate with the blastocyst 22 quality, ploidy status, implantation potential and clinical outcomes, but can differentiate between 23 aneuploid and euploid blastocysts.24 What we already know 25 mtDNA levels in the trophectodermal cells have been suggested to be associated with blastocyst 26 morphology, ploidy and implantation rates, and has been proposed as biomarker to access 27 blastocyst quality and predict clinical outcomes. However, discrepancies exist if mtDNA levels 28 could serve as a marker for the same.29 Study design and duration 30

The Role of Mitochondria in Human Fertility and Early Embryo Development: What Can We Learn for Clinical Application of Assessing and Improving Mitochondrial DNA?

“…Even now, there are a lot of controversies as conducted studies have reached conflicting results (Table 1). Most study groups assessing the relationship of mtDNA content and embryo's ploidy status agree that increased levels of mtDNA correlate with aneuploidy [38,73,76,78,87,89]. Nevertheless, the mechanisms leading to such an effect are still not known.…”

“…Divergent results were also obtained for assessment of the relationship of the mitochondrial score with embryos' morphology and especially maternal age [38,[73][74][75][76][77][78][79][80][81][82][83][84][85][86][87][88][89][90][91].…”

“…The parameter, commonly called mitochondrial score, was defined as the ratio of mitochondrial/nuclear DNA copy number. However, almost every study group differently calculated its value [ 38 , 73 , 74 , 75 , 76 , 77 , 78 , 79 , 80 , 81 , 82 , 83 , 84 , 85 , 86 , 87 , 88 , 89 , 90 , 91 ]. Even now, there are a lot of controversies as conducted studies have reached conflicting results ( Table 1 ).…”

“…Most study groups assessing the relationship of mtDNA content and embryo’s ploidy status agree that increased levels of mtDNA correlate with aneuploidy [ 38 , 73 , 76 , 78 , 87 , 89 ]. Nevertheless, the mechanisms leading to such an effect are still not known.…”

“…The primary aim of conducted experiments was to evaluate the link of mtDNA levels and the embryo’s ability to implant [ 38 , 73 , 74 , 75 , 77 , 78 , 79 , 80 , 81 , 82 , 83 , 84 , 85 , 86 , 87 , 91 ]. Indeed, the proof of such a relationship would be a revolutionary discovery, giving the possibility to identify viable embryos and in consequence significantly improve the pregnancy rates of in vitro fertilisation treatment.…”