Introduction Blastocyst biopsy has been the standard practice at Genea for the last 15 years. In contrast, the technology used for embryo culture and the analysis of biopsied tissue samples has changed markedly. Most recently, the introduction of continuous culture with imaging capabilities (Geri, Genea Biomedx) and Next Generation Sequencing (NGS; Illumina VeriSeq) have combined to have a positive impact on our ability to detect abnormal ploidy states. Materials & Methods To control for staggered implementation times of new technologies, the dataset used in this study was confined to cycles undergoing PGT-A at our main clinic. IVF/ICSI cycle and PGT-A data since the start of 2014 were retrospectively analyzed, representing a period of approximately two years before and after the introduction of NGS and Geri. The rates of abnormal fertilization events identified by fertilization checks and by PGT, as well as clinical outcomes, were assessed. Results Implementation of PGT-A by NGS improved detection rates for triploid 69XXY and 69XYY embryos, with a total of 56 identified. However, the trend of increased triploid detection is now reversing, which correlates with improved detection of 3PN fertilization events due to time-lapse imaging. Although 50% of embryos in the study group were derived from ICSI, 70% of triploid results were from IVF insemination. Roll out of continuous culture with time-lapse capabilities has also correlated with an increase in the proportion of monopronuclear (1PN) embryos detected at fertilization check, with an overall rate of 5%. Increased uptake of PGT-A, combined with better education regarding the options for testing of 1PN embryos, has resulted in increased detection of abnormal 1PN blastocysts. 1PNs returning a PGT-A result of NAD XY were considered normal, whereas 70 apparently balanced NAD XX embryos were further tested by STR analysis. Abnormal fertilization events were confirmed for ten of these, seven of which had maternal only and three paternal only contributions. Although 65% of tested 1PN embryos were derived from IVF insemination, all except one (maternal only) of the verified abnormal fertilization events were ICSI inseminations. Transfer of 39 1PN embryos with confirmed biparental inheritance has resulted in 18 biochemical pregnancies, 15 of which proceeded to a fetal heartbeat, with 13 live births to date. Conclusions IVF fertilized embryos that develop to a biopsiable blastocyst appear to have a very low risk of being true 1PNs, but have an increased chance of being triploid relative to ICSI. In contrast, a significant proportion of tested 1PN ICSI embryos were confirmed to have monoparental inheritance. Given that paternal only 1PNs derived from a Y sperm will not develop, our results suggest that monoparental ICSI embryos arise with equal frequency from maternal only and paternal only events. Overall, our experience indicates that implementation of continuous culture with imaging capabilities, combined with encouraging patients to consider the option of PGT, can decrease the risk of transferring an embryo with abnormal ploidy status, while also improving overall cycle success rates by making many 1PN embryos available for clinical use.