The author has requested that the original article entitled "Genotyping Analysis of Circulating Fetal Cells Reveals High Frequency of Vanishing Twin Following Transfer of Multiple Embryos" that was published in the April-June 2013 issue of Avicenna Journal of Medical Biotechnology (AJMB) be withdrawn because the results were published without the co-workers being aware of this publication. Therefore this paper is retracted, considering the fact that it is contrary to the scientific rules and unrespectful of the contribution of the other authors.