General results are shown in Table I. A total of 2809 (2718 fresh and 91 frozen–thawed) mature oocytes were injected with a fertilization rate of 75.5% (N = 2120), leading to the development of 2102 embryos. Other 24 frozen embryos, previously vitrified without any genetic testing, were successfully warmed. A total of 2126 embryos were cultured with a blastocyst formation rate of 52.8% (N = 1122); all of them were biopsied from Day 4 to Day 7 of culture. A higher blastocyst formation rate was obtained in monogenic disease compared to chromosomal rearrangement cycles (56.3 vs 48.8%, P < 0.001, respectively). After the genetic analysis, 309 (27.5%) blastocysts resulted transferable, in total for monogenic disease or chromosomal rearrangement and for their ploidy status, 42 (3.7%) were mosaic diploid/aneuploid, 55 (4.9%) had no conclusive result and 716 (63.8%) were not transferable, being affected by a genetic disease or a chromosomal abnormality and/or for their ploidy status. Of note, 35.7% (N = 400) of the blastocysts were not transferable after the PGD analysis and this percentage increased to 63.8% (N = 716) when they were also analyzed by means of PGS (Mc Nemar test P < 0.001; Figure 1A). Furthermore, 316 blastocysts (50.6% of transferable blastocysts after PGD and 28.2% of total number of biopsied blastocysts) resulted healthy for the examined genetic disease or for the parental chromosomal abnormality were however aneuploid. Out of the 304 PGD/PGS cycles, 39.8% (N = 121) resulted with affected and/or aneuploid blastocysts only and thus without the possibility to perform any embryo replacement (Table I). The percentage of cycles without available blastocysts for transfer was 28.6% (N = 87) after PGD analysis and another 11.2% (N = 34) of the cycles were canceled after PGS analysis, resulting in a significant increase in cycles without transferable blastocysts (Mc Nemar test P < 0.001; Figure 1B). Clinical results are shown in Table II. A total of 202 embryo transfers were performed in 167 patients, 53 fresh and 149 cryopreserved, where 218 healthy or carrier euploid blastocysts were transferred. To date, 66 deliveries occurred with 70 healthy babies born; 35 males and 35 females; 13 pregnancies are still ongoing and 91 euploid healthy blastocysts are still cryopreserved waiting to be transferred. A higher percentage of premature babies (≤37 weeks of gestation and/or ≤2500 g at birth) was found in cycles performed for chromosomal abnormality reasons (28.6%) compared to monogenic disorders (7.1%, P = 0.022). No significant differences were detected in the gender of the newborns. No adverse outcomes, such as perinatal deaths or birth defects, were obtained (Table II). A comparison between fresh and cryopreserved embryo transfer outcomes is reported in Supplementary material(Supplementary Table S2).