title: Mitochondrial DNA in Day 3 embryo culture medium is a novel, non-invasive biomarker of blastocyst potential and implantation outcome.
abstract: In assisted reproduction technology, embryo competence is routinely evaluated on morphological criteria. Over the last decade, efforts in improving non-invasive embryo assessment have looked into the secretome of embryos. Human embryos release genomic DNA (gDNA) and mitochondrial DNA (mtDNA) into the culture medium, and the mtDNA/gDNA ratio is significantly correlated with embryo fragmentation. Here, we investigate whether mtDNA/gDNA ratio in embryo spent medium is correlated with blastulation potential and implantation. The mtDNA/gDNA ratio was assessed in 699 Day 3 culture media by quantitative polymerase chain reaction (qPCR) to investigate its correlation with embryo morphology, blastocyst development and implantation. A logistic regression model evaluated whether mtDNA/gDNA ratio in the secretome may improve the prediction of blastulation. We found that embryos that successfully developed into blastocysts exhibited a significantly higher mtDNA/gDNA ratio in the culture medium compared with those that arrest (P = 0.0251), and mtDNA/gDNA, combined with morphological grading, has the potential to predict blastulation better than morphology alone (P = 0.02). Moreover, mtDNA/gDNA ratio was higher in the media from good-quality embryos that reached the full blastocyst stage on Day 5 compared with those that developed more slowly (P < 0.0001). With respect to blastocyst morphology, higher trophectoderm quality was associated with a higher mtDNA/gDNA ratio in the culture medium. Finally, a high mtDNA/gDNA ratio in spent medium was associated with successful implantation outcome (P = 0.0452) of good-quality embryos. In summary, the mtDNA/gDNA ratio in the Day 3 embryo secretome, in combination with morphological grading, may be a novel, non-invasive, early biomarker to improve identification of viable embryos with high developmental potential.
authors.affiliation: UOS Physiopathology of Human Reproduction, IRCCS AOU San Martino-IST, Largo R. Benzi, 10, 16132 Genoa, Italy.
authors.forename: S
authors.initials: S
authors.lastname: Stigliani
authors.affiliation: Department of Economics and Business Studies, University of Genoa, Genoa, Italy.
authors.forename: L
authors.initials: L
authors.lastname: Persico
authors.affiliation: Department of Economics and Business Studies, University of Genoa, Genoa, Italy.
authors.forename: C
authors.initials: C
authors.lastname: Lagazio
authors.affiliation: UOS Physiopathology of Human Reproduction, IRCCS AOU San Martino-IST, Largo R. Benzi, 10, 16132 Genoa, Italy.
authors.forename: P
authors.initials: P
authors.lastname: Anserini
authors.affiliation: UOS Physiopathology of Human Reproduction, IRCCS AOU San Martino-IST, Largo R. Benzi, 10, 16132 Genoa, Italy University of Genoa, Genoa, Italy.
authors.forename: P L
authors.initials: PL
authors.lastname: Venturini
authors.affiliation: UOS Physiopathology of Human Reproduction, IRCCS AOU San Martino-IST, Largo R. Benzi, 10, 16132 Genoa, Italy paola.scaruffi@hsanmartino.it.
authors.forename: P
authors.initials: P
authors.lastname: Scaruffi
mesh_terms: D001755:Blastocyst / Q000378:metabolism* / Q000473:pathology; D002470:Cell Survival; D003470:Culture Media / Q000378:metabolism*; D004272:DNA, Mitochondrial / Q000235:genetics / Q000378:metabolism*; D046149:Embryo Culture Techniques; D010064:Embryo Implantation; D004624:Embryo Transfer; D005819:Genetic Markers; D006801:Humans; D016015:Logistic Models; D016133:Polymerase Chain Reaction; D011237:Predictive Value of Tests; D013997:Time Factors
chemical_list: D003470:Culture Media; D004272:DNA, Mitochondrial; D005819:Genetic Markers
keywords: blastocyst; cell-free DNA; human embryos; implantation; mtDNA