To evaluate the post-biopsy developmental outcome of normal and abnormal embryos according to their preimplantation genetic screening (PGS) results. Retrospective analysis in a university tertiary center. A total of 165 embryos (16 cycles-mean patient's age 34.8 ± 5.1) were submitted to 24-chromosome PGS via array CGH (aCGH) or Single Nucleotide Polymorphism (SNP). The indications for PGS were recurrent pregnancy loss (RPL), advanced maternal age (AMA) and multiple IVF failure. Single blastomeres were biopsied on day 3. An historical cohort of embryos (n = 219) tested by FISH (9-chromosome probes) for patients with the same indications was used for comparison of technologies. Out of 165 embryos biopsied, 140 (85%) had sufficient DNA for informative analysis. Twenty-five embryos (18%) were normal and 115 (82%) abnormal. Interestingly, only 12 (48%) of the normal embryos developed to blastocyst stage, while the remaining 13 (52%) either completely arrested (6 embryos) after the biopsy or progressed but failed to reach blastocyst stage (7 embryos). Among the 115 abnormal embryos, 22 (19%) reached blastocyst stage while the remaining 93 (81%) either completely arrested (38 embryos) after the biopsy or failed to reach blastocyst stage (55 embryos). Blastocyst development rate between normal (48%) and abnormal embryos (19%) was statistically significant (P=0.005). Of the 16 cycles, 9 (56%) resulted in transfers with 7 clinical pregnancies (43%) of which 4 ongoing, 2 live birth and 1 miscarriage. With FISH (historical controls), 23% (n = 50) and 77% (169), of the embryos were normal and abnormal, respectively. The new PGS technologies increased the detection rate for embryo abnormality from 77% to 82% in patients with RPL, AMA and multiple IVF failures. It is intriguing that in this patient population a high number of normal embryos (52%) fail to reach blastocyst stage, perhaps suggesting non chromosomal (but genetic) or other mechanisms responsible for embryo arrest.