Effect of transferring a morphologically impaired embryo with a good quality embryo on the pregnancy and implantation rates.

OBJECTIVE: This study aimed to investigate the effect of transferring embryos with different qualities on pregnancy and implantation rates. PATIENTS AND METHODS: In a retrospective multi-center study we analyzed 761 patients aged ≤ 35 years who had an elective transfer of one or two embryos. Embryos were scored morphologically by their developmental stage into good "A" and impaired "B" embryos. Pregnancy and implantation rates were compared between patients who had a transfer of: one grade "A" embryo; two grade "A" embryos, two embryos one grade "A" plus one grade "B" embryos; one grade "B" embryo and two grade "B" embryos. RESULTS: Higher pregnancy and implantation rates were observed in patients who had received one embryo of grade "A" (34.6%) and two grade "A" embryos (45.2%, 25.85% respectively), compared to patients who received two embryos, one of grade "A" plus one of grade "B" (25%, 13.77% respectively). CONCLUSIONS: Transferring a morphologically and developmentally impaired embryo, significantly lower the implantation chance of the good quality embryo.