The association between quality of supernumerary embryos in a cohort and implantation potential of the transferred blastocyst.

Our findings suggest that quality of supernumerary embryos is associated with IR of the transferred embryo, among patients with ≥ 3 blastocysts available on day 5. As cohort quality declines and the proportion of low implantation potential embryos increases, the IR of the transferred embryo declines. These associations are attenuated when controlling for quality of the transferred embryo, suggesting that the relationship between embryo cohort quality and implantation is not independent of the transferred embryo quality.