Integrating PGT-A into PGT-M protocols in young ART-naïve patients undergoing single embryo transfer

What are the effects of integrating preimplantation genetic testing for aneuploidy into preimplantation genetic testing for monogenic/single gene disorders (PGT-M), termed 'comprehensive PGT' (coPGT-M)?

A retrospective cohort of frozen embryo transfer cycles, derived from intracytoplasmic sperm injection, with single embryo transfers (SET) performed between 2019 and 2022 in patients undergoing their first round of assisted reproductive technology. CoPGT-M was implemented from July 2021. Only cycles with at least one biopsied blastocyst were included. Outcomes were compared between 701 embryos from 126 PGT-M cycles and 801 embryos from 131 coPGT-M cycles.

The median female age at oocyte retrieval was similar between the PGT-M and coPGT-M cohorts [29.5 (IQR 27.0-33.0) versus 29.5 (IQR 28.0-33.0) years], as were male age, body mass index, and anti-Müllerian hormone concentration. The PGT-M cohort had a significantly lower median number of cumulus-oocyte complexes [15.0 (IQR 10.0-20.0) versus 15.5 (IQR 11.0-26.0); P = 0.039], while the number of zygotes, blastocysts biopsied, and blastocysts eligible for transfer after genetic analysis were comparable. The percentage of cycles resulting in at least one live birth (PGT-M 42.1% versus coPGT-M 51.9%) and the median number of embryo transfers required to reach the first live birth among patients who achieved a live birth [PGT-M 1 (IQR 1-2) versus coPGT-M 1 (1-2)] were comparable. Generalized estimating equation analysis, adjusted for embryo quality, showed higher odds of live birth per SET [adjusted OR (aOR) 1.86, 95% CI 1.21-2.87; P = 0.005] and lower odds of pregnancy loss (aOR 0.50, 95% CI 0.27-0.93; P = 0.028) in the coPGT-M cohort.

While cumulative outcomes per cycle were similar, coPGT-M was associated with significantly higher odds of live birth per embryo transfer and lower risk of pregnancy loss, indicating clinical benefit, even in younger patients.