Cohort aneuploidy rates are not predictive of sustained implantation rate of euploid blastocysts: give that blastocyst a chance!


      Comprehensive chromosome screening (CCS) enhances pregnancy rates and outcomes by allowing for the selection of euploid embryos. While implantation rates (IR) are dramatically improved, factors beyond aneuploidy are involved in reproductive competence as a substantial number of euploid embryos fail to implant. This can make patient counseling complex, especially when the prevalence of aneuploidy is particularly high or low. This study aims to determine if the overall aneuploidy rate (AR) exerts a cohort effect on the implantation rate of euploid blastocysts selected for transfer, thus impacting implantation rate.



      Materials and Methods

      All patients who had CCS performed were included. Results from all evaluated embryos were used to determine the cohort AR. Outcomes from all embryos transferred from that cohort were included to calculate the sustained IR, as defined by the number of fetal heart beats seen at the time of discharge to obstetric care. Patients were stratified by overall AR and outcomes compared. ANOVA was used for statistical analysis.


      743 patients underwent transfer of 1295 euploid embryos. Sustained IR was not impacted by the aneuploidy rate of the cohort as a whole (P=0.28).
      Tabled 1Aneuploidy Rate and Sustained Implantation Rate
      AR groupnSustained IRSE


      Background aneuploidy rate does not appear to exert a negative cohort effect when transferring euploid blastocysts. Even patients with extremely high overall aneuploidy rates have excellent sustained implantation rates if a euploid blastocyst is transferred. As such, patients with a single euploid blastocyst should not be discouraged from proceeding with transfer, nor should they empirically increase transfer order. At the other extreme, patients with a high proportion of euploidy should not be concerned that another major factor will limit their outcomes and should proceed with conservative transfers.