Preimplantation genetic diagnosis and the biopsy technique: Important considerations

Abstract
Preimplantation genetic diagnosis allows to test the genetic status of embryos prior to implantation. In order to obtain genetic material, on which carry out a genetic diagnosis, a procedure named embryo biopsy is required. In the last two decades, embryo biopsy at the cleavage stage has been the mostly performed procedure. However, recently, alternative methods allowing the retrieval of a larger number of cells (blastocyst stage biopsy), or representing a valid alternative to overcome ethical issues (polar body biopsy) have obtained increasing consensus. This article reviews different methods of embryo biopsy and points out their positive and negative aspects.