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Tremendous advances in genetics have transformed the field of reproductive endocrinology and infertility over the last few decades. One of the most prominent advances is preimplantation genetic testing (PGT), which allows for the screening of embryos obtained during in vitro fertilization before transfer. Moreover, PGT can be performed for aneuploidy screening, detection of monogenic disorders, or exclusion of structural rearrangements. Refinement of biopsy techniques, such as obtaining samples at the blastocyst rather than the cleavage stage, has helped optimize results from PGT, and technological advances, including next-generation sequencing, have made PGT more efficient and accurate. The continued evolution of the approach to PGT has the potential to further enhance the accuracy of results, expand the application to other conditions, and increase access by reducing cost and improving efficiency. [ABSTRACT FROM AUTHOR]

Objective: To develop a novel and robust protocol for multifactorial preimplantation genetic testing of trophectoderm biopsies using quantitative polymerase chain reaction (qPCR).Design: Prospective and blinded.Setting: Not applicable.Patient(s): Couples indicated for preimplantation genetic diagnosis (PGD).Intervention(s): None.Main Outcome Measure(s): Allele dropout (ADO) and failed amplification rate, genotyping consistency, chromosome screening success rate, and clinical outcomes of qPCR-based screening.Result(s): The ADO frequency on a single cell from a fibroblast cell line was 1.64% (18/1,096). When two or more cells were tested, the ADO frequency dropped to 0.02% (1/4,426). The rate of amplification failure was 1.38% (55/4,000) overall, with 2.5% (20/800) for single cells and 1.09% (35/3,200) for samples that had two or more cells. Among 152 embryos tested in 17 cases by qPCR-based PGD and CCS, 100% were successfully given a diagnosis, with 0% ADO or amplification failure. Genotyping consistency with reference laboratory results was >99%. Another 304 embryos from 43 cases were included in the clinical application of qPCR-based PGD and CCS, for which 99.7% (303/304) of the embryos were given a definitive diagnosis, with only 0.3% (1/304) having an inconclusive result owing to recombination. In patients receiving a transfer with follow-up, the pregnancy rate was 82% (27/33).Conclusion(s): This study demonstrates that the use of qPCR for PGD testing delivers consistent and more reliable results than existing methods and that single gene disorder PGD can be run concurrently with CCS without the need for additional embryo biopsy or whole genome amplification. [ABSTRACT FROM AUTHOR]

Objective: To investigate the applicability of next-generation sequencing (NGS) to preimplantation genetic diagnosis (PGD); to evaluate semiconductor-based NGS for genetic analysis of human embryos. Design: Blinded. Setting: Academic center for reproductive medicine. Patient(s): Six couples at risk of transmitting single-gene disorders to their offspring. Intervention(s): None. Main Outcome Measure(s): Embryonic genotype consistency of NGS with two independent conventional methods of PGD. Result(s): NGS provided 100% equivalent PGD diagnoses of compound point mutations and small deletions and insertions compared with both reference laboratory– and internally developed quantitative polymerase chain reaction (qPCR)–based analyses. Furthermore, NGS single-gene disorder screening could be performed in parallel with qPCR-based comprehensive chromosome screening. Conclusion(s): NGS can provide blastocyst PGD results with a high level of consistency with established methodologies. This study and its design could serve as a model for further development of this important and emerging technology. [ABSTRACT FROM AUTHOR]