Day of embryo transfer

Abstract

With the development and the subsequent clinical validation of physiological culture systems over the past decade, it has become possible to culture, as a matter of routine, the human embryo to the blastocyst stage. Prior to these advances it was simply not feasible to grow the human embryo routinely past the eight-cell stage in the laboratory. Consequently, during the first 20 years of clinical IVF embryo transfers have been performed on days 1 to 3, the former being the choice primarily when laboratory conditions were unfavorable [1]. Given that sufficient investment in the embryology laboratory has been undertaken [2] and that sufficient quality control and quality assurance procedures ar..