To report our clinical experience with embryos identified as polyploid via abnormal sex chromosome ratios. Polyploid embryos contain more than two sets (n) of chromosomes (e.g. triploid (3n) and tetraploid (4n)) and often miscarry. Those that survive to term typically only live a few days. Triploidy accounts for ∼1% of all conceptions and ∼10% of miscarriages. Tetraploidy is rare. Types of triploidy include digynic fertilization (2 of 3 sets maternally derived; diploid ovum) or diandric (2 of 3 sets paternally derived; diploid sperm or fertilization by 2 sperms (dispermy)). Most PGS technologies cannot reliably detect all types of polyploidy, but can detect embryos with unbalanced sex chromosome ratios (69,XXY; 69,XYY; some forms of tetraploidy). Here, we characterize the types of polyploidy detected. Trophectoderm biopsies from >30,000 embryos were analyzed using a targeted NGS-based assay. Utilizing chromosome copy number calls for autosomes and sex chromosomes, we identified embryos expected to be polyploid. Using NGS single nucleotide polymorphism (SNP) information, we confirmed the polyploidy calls and stratified the data by oocyte age, clinical indication, and fertilization type. We identified 203 likely polyploid embryos based on unbalanced sex chromosome ratios; <1% of tested embryos. Likely polyploid embryos were seen in all age groups between 23-45 (ranging from 0.2-1.5%) and did not increase with maternal age. Of interest, 6 patient cycles had more than one polyploid embryo, 2 of which were egg donor cycles. A subset of the likely polyploid embryos were studied using NGS-based SNP analysis and, for embryos with enough informative SNPs, 74% were confirmed as polyploid based on allelic ratios.Of the 127 confirmed polyploid embryos, the majority were triploid (119) and eight were tetraploid. Consistent with previous reports, most triploid embryos were XXY (117) vs XYY (2). All tetraploids were XXXY (8). About half of all polyploidy embryos had another chromosome abnormality. Of the polyploid embryos where fertilization type was known, 81.3% had undergone ICSI meaning dispermy can be ruled out. Identifying embryos with the greatest chance of implantation and live birth is vital to improve IVF success rates. Detection of polyploid embryos is essential to decreasing miscarriage rates in PGS-derived pregnancies. In this dataset, the incidence of polyploidy did not correlate with patient age or fertilization type. Given the technical limitations of many PGS assays, some forms of polyploidy go undiagnosed (69,XXX; 92,XXXX; 92,XXYY); however, forms with skewed sex chromosome ratios are likely picked up and diagnosed as aneuploid. Here we use a combination of sex chromosome ratios and targeted NGS-based SNP analysis to confirm the presence of 69,XXY, 69,XYY and 92,XXXY in a subset of samples. This technology can be validated to detect other types of currently undetectable polyploidy, increasing the accuracy of NGS-PGS.