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.