Periimplantational events post-IVF

The rate of occurrence of pregnancy following IVF-ET (in vitro fertilization plus embryo transfer) is still very low considering the advancement of human IVF technology in the last ten years. Unrecognized variation in embryo quality is oft cited as the main factor involved in this low success rate. However, the picture is probably more complex than this, involving many factors that have a bearing on the periimplantational period following transfer of IVF embryos. Six general areas are discussed in relation to their relative significance to implantation, and the concept of an interrelated continuum of periimplantational events is proposed as a prerequisite to predictably successful implantation post-IVF.