Comparative Age-Stratified Analysis of Live-Birth Outcomes in Primary Embryo Transfer to Assess the Effect of Preimplantation Genetic Testing for Aneuploidy

OBJECTIVE: To investigate whether the perceived advantages of preimplantation genetic testing for aneuploidy (PGT-A) are attributable to genetic testing itself or to transferring a thawed frozen embryo into a receptive endometrium. We compared live-birth and cumulative live-birth outcomes across three groups: primary frozen embryo transfer (FET) with PGT-A, FET without PGT-A, and fresh transfers in initial autologous assisted reproductive technology (ART) cycles. METHODS: We performed a retrospective analysis from the 2014-2020 Society for Assisted Reproductive Technology Clinic Outcome Reporting System database, comparing success rates of primary FET with PGT-A, FET without PGT-A, and fresh transfers. Live birth, cumulative live birth, and miscarriage rates were compared, with primary transfer defined as the first transfer after the index retrieval. Live-birth rate was defined as the likelihood of live birth from the first transfer; cumulative live-birth rate was the likelihood of a live birth from all transfers within 1 year of the initial retrieval. Multivariate logistic regression determined the association of live birth with FET with PGT-A, FET without PGT-A, and fresh transfers while controlling for various demographic and clinical factors. RESULTS: We examined 263,521 first autologous ART cycles between 2014 and 2020 that resulted in primary embryo transfer. The live-birth rate was 56.0% for FET with PGT-A, 48.3% for FET without PGT-A, and 39.8% for fresh transfers ( P <.001). Cumulative live-birth rates were similar between the two frozen strategies (74.1% with PGT-A vs 74.0% without PGT-A, P =.66); both were higher than fresh transfers (60.0%, P <.001). In patients younger than age 38 years, cumulative live-birth rates were higher for FETs without PGT-A ( P <.01). In those 38 years and older, PGT-A was associated with higher cumulative success ( P <.001). Regression analysis demonstrated that FET, regardless of PGT-A use, was associated with higher odds of live birth across all age groups, whereas PGT-A conferred additional benefit only in patients aged 35 years or older, with increasing advantage with advancing age. CONCLUSION: Primary FETs were associated with better outcomes than fresh transfers. Although PGT-A use improved outcomes for older patients, no overall benefit was seen in younger patients. These findings bring into question the perceived advantage of PGT-A over FETs without PGT-A, particularly in those younger than age 38 years, in whom FET without PGT-A demonstrated a higher cumulative live-birth rate compared with cycles with PGT-A. These data highlight the need for cautious consideration of PGT-A utilization for initial transfer, especially in younger age groups.