In a recent study, the investigators observed a 1.6 fold increase (p < 0.001) in implantation rate when aCGH was applied to blastocyst embryos (Schoolcraft et al. 2010). The test group used CGH, an older and less sensitive iteration of the technique to be used in the proposed study - array CGH. Array CGH has a 6 megabase resolution and screens for 30% of all DNA bases (compared to 0.1% of SNP arrays). With array CGH the false positive and false negative rate is 0% when biopsying blastocysts, and 3% when biopsying day 3 embryos (Gutierrez Mateo et al, 2011). Based on our preliminary data, patients with 5 or more day 3 embryos and less than 43 years of age are the most likely to benefit from PGD, since they produce enough embryos and enough normal embryos so a selection technique, like PGD could chose them and improve their reproductive odds.