ABSTRACT
Blastocyst culture and transfer are strongly desired, as they allow for increased embryo selection and consequently lead to significantly improved implantation and live birth rates (1). In contrast, cleavage-stage transfer programs are now more often finding themselves at a disadvantage. Transferring at the cleavage stage mostly necessitates the transfer of multiple embryos to be competitive and, as a result, is plagued with multiple implantations. Furthermore, the practice of transferring multiple cleavage-stage embryos does not easily lead to higher live birth rates anymore.
