Abstract

On 2013 for the first time, we discovered both cell-free genomic DNA (cf-gDNA) and cellfree mithocondrial DNA (cf-mtDNA) in spent culture media of human cleavage-stage embryos [1]. Analysis of DNA profiles of day 3 spent media demonstrated that cf-mtDNA/cf-gDNA ratio was correlated with embryo quality, and in particular it was significantly associated with degree of embryo fragmentation. Based on our results, the higher cf-mtDNA/cf-gDNA ratio was associated with blastocyst’s developmental competence, trophoectoderm quality, and implantation [2]. In a prospective, blinded, multi-centric study we confirmed that the cf-mtDNA/cf-gDNA ratio in day 3 spent culture medium, combined with embryo morphology, improved the prediction upon blastulation compared to morphology alone, without any influence from patient and treatment-related factors [3].