Impact of the addition of Early Embryo Viability Assessment to morphological evaluation on the accuracy of embryo selection on day 3 or day 5: a retrospective analysis

In this study we aimed at retrospectively assessing in a homogeneous group of IVF patients whether the addition of Early Embryo Viability Assessment (Eeva™) to standard morphology increases the accuracy of embryo selection in case of double embryo transfer (DET) on day 3 or single embryo transfer (SET) on day 5. Eeva™ is an algorhythm aimed at indicating on day 3, according to morphokinetic parameters observed in the first three days of embryo growth, which embryos are more likely to develop into viable blastocysts and implant. A total number of 328 patients were included in the study; IVF or ICSI were performed and 428 embryos were transferred, either with DET on day 5, or (when at least four top scored embryos were available on day 3) with SET of day 5. Four groups were considered: (a) patients receiving day 3 DET with embryos selected by standard morphology (DET-3 M, n = 106, receiving 212 embryos), (b) patients receiving day 3 DET with embryos selected by morphology plus Eeva™ (DET-3 ME group, n = 48, receiving 96 embryos), (c) patients receiving day 5 SET with a blastocyst selected by standard morphology (SET-5 M group, n = 126, receiving 126 embryos), and (d) patients receiving day 5 SET with a blastocyst selected by morphology plus Eeva™ (SET-5 ME group, n = 48, receiving 48 embryos). Overall, a clinical pregnancy rate of 49.1%, implantation rate of 40%, and ongoing pregnancy rate of 43.6% were observed. The implantation rate was significantly higher in DET-3 ME group than in DET-3 M group (44.8% vs. 30.2%, p < 0.02), whereas it was comparable in groups DET-3 ME, SET-5 M and SET-5 ME. Differently, the ultrasound-verified clinical pregnancy rate and the ongoing pregnancy rate at 12 weeks did not significantly differ in all four groups. Overall, our findings suggest that Eeva™ algorhythm can improve embryo selection accuracy of standard morphology when ET on day 3 is scheduled, leading to a higher implantation rate, but its impact on ongoing pregnancy and live birth needs to be further clarified.