Use of preimplantation genetic testing for monogenic disorders and subsequent prenatal care and diagnostic testing.

Objective: The goal of preimplantation genetic testing for monogenic or single gene defects (PGT-M) is to identify inherited pathogenic variants in the embryo prior to embryo transfer, increasing the likelihood of an unaffected child. Prenatal diagnostic testing is recommended to confirm the results of PGT-M. The purpose of this study was to characterize the population undergoing PGT-M over time.

Methods: This retrospective study examined patients who had a positive pregnancy test after PGT-M from 2012 to 2019. A query of the internal assisted reproductive technology database and chart review were used.

Results: One hundred and 42 patients completed IVF cycles for PGT-M during this time period and progressed past 10 weeks gestation. There were more PGT-M cycles over time with 46 cycles between 2012 and 2015 and 96 cycles between 2016 and 2019. Patients varied on the decision to pursue prenatal diagnostic testing after PGT-M. For those with known follow-up (130/142), 16 patients underwent diagnostic testing (12%) and 114 did not.

Conclusion: As PGT-M is increasingly utilized prior to pregnancy, it is important for genetic counselors and OB/GYNs to understand the characteristics and outcomes of the population of patients undergoing PGT-M, including how to counsel about the residual risk of an affected pregnancy after PGT-M.