Received March 02, 1997
Accepted May 17, 1997

Introduction : Preimplantation diagnosis has been used to detect genetically transmitted diseases in order to avoid transmission to offspring. The amplification of the blastomeres DNA can be achieved by PCR analysis. 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 analyzed the possibility of DNA amplification of trophectoderm cells stage blastomeres. Material and Methods: A total of 50 embryos were biopsied on day 3 after lCSI. 25 blastomeres presented amplification and the confirmation of the result were obtained after amplification of the other blastomeres of the same embryo. Results: Confirmation was obtained in 76%. A total of 13 blastomeres were male and 9 female. In ali cases where trophectoderm cell were analyzed confirmation was found. When we used SRY sequence for amplification, we found 72% failure. When we used amelogenine sequence the failure rate was 20%. Conclusion: Our results confirm the possibility to biopsy human embryos at day 3 and to amplify the blastomeres by PCR analysis. Moreover, we show the possibility of amplification of trophectoderm cell with high accuracy. This results demonstrate lhe possibility of achieving a greater number of cells available for analysis 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 transferred in a later cycle.