Preimplantation Genetic Diagnosis Using Blastocyst Biopsy and Array CGH

The investigators propose to perform a clinical randomized trial to evaluate the effect of single embryo (blastocyst) transfer (SET) with array CGH for the evaluation of the complete chromosome complement of the blastocyst in comparison to standard ART methods in which one or more embryo are replaced. Patients will be randomized into two groups: * Control group: patients will have up to two embryos replaced on day 5 based on morphological and developmental characteristics, and the other embryos reaching blastocyst stage will be vitrified. If patients in the control group do not have a pregnancy to term from that fresh cycle, they will be offered free PGD either for the frozen embryos of that cycle or for the next cycle (up to the center and patient). Data from that PGD is not part of the study. * Test group: patients will have grade A,B or C blastocysts hatched on day 5, biopsied on day 5, analyzed by array CGH, and a single euploid embryo transferred on day 6. Any morulas developing to grade A,B or C blastocyst on day-6 will be also analyzed but vitrified for use in a future cycle.