Received November 26, 2005
Accepted November 29, 2005

INTRODUCTION:Preimplantation diagnosis has been used to detect geneticaly transmited diseases in order to avoid transmission to offspring. The amplification of the blastomeres DNA can be achieved by PCR analisys. The objectives of our study is to perform cleavage stage embryo biopsy and posterior PCR analisys of the blastomeres for sex determination. We have also analised the possibility of DNA amplification of trophectoderm cells stage blastomeres. MATERIAL AND METHODS:A total of 50 embryos were biopsied on day 3 after ICSI. 25 blastomerse presented amplification and the confirmation of the result were obtained after amplification of the other blastomeres of the same embryo. Confrmation was obtained in 76%. A total of 13 blastomeres were inale and 9 female. In all cases where trophectoderm cell were analised confirmation was found. When we used SRY sequente for amplification, we found 72% failure. When we used amelogenine sequente the failure rate was 20%. CONCLUSION: Our results confirm the possibility to biopsy human embryos at day 3 and to amplify lhe blastomeres by PCR analisys. Moreover, we show the possibility of amplification of trophectoderm cell with high accuracy. This results demonstrate the possibility of aehieving a greater number of cells available for analisys in order to improve the amplification accuracy, and transfer embryos at the blastocyst stage Embryos can also be frozen at day 3 and non affected transfered in a later cycle.