Cycle characteristics of day 3 embryo transfers with 4-cell embryos only.

PurposePatient and cycle characteristics of day 3 transfers with developmentally lagging 4-cell embryos only were analyzed and related to the outcome of a live birth.MethodsDay 3 transfers with either 4-cell embryos only (study group; n = 138) or 8-cell embryos only (control group; n = 282) were compared retrospectively.ResultsThe total dose of FSH per treatment was higher, while the number of oocytes, zygotes, and transferred embryos was lower in the study group cycles compared to controls. The implantation, pregnancy, and live birth rates were dramatically lower in the study group compared to the control group. In the study group, the few cycles resulting in a live birth were characterized by a normal ovarian response to stimulation, similar to that of control group cycles with- or without a live birth.ConclusionsIn cycles characterized by intensive ovarian stimulation, but poor response, the chance for a live birth is extremely low after day 3 transfer of 4-cell embryos.