What next for preimplantation genetic screening? A polar body approach!

Screening of human preimplantation embryos for numerical chromosome abnormalities has been conducted mostly at the preimplantation stage using fluorescence in situ hybridization. However, it is clear that preimplantation genetic screening (PGS) as it is currently practiced does not improve live birth rates. Therefore the ESHRE PGS Task Force has decided to start a proof of principle study with the aim of determining whether biopsy of the first and second polar body followed by subsequent analysis of the complete chromosome complement of these polar bodies using an array based technique enables a timely identification of the chromosomal status of an oocyte. If the principle of this approach can be proven, it is obvious that a multicentre randomized controlled trial should then be started to determine the clinical value of this technique. In this way the ESHRE PGS Task Force hopes to redirect preimplantation screening from the blind alley to the main road of assisted reproduction.