Preimplantation genetic testing for aneuploidy on previously cryopreserved unbiopsied blastocysts: a cohort study in women with IVF pregnancy loss.

Abstract

Research question: Does preimplantation genetic testing for aneuploidy (PGT-A) on cryopreserved unbiopsied blastocysts improve pregnancy outcomes for women with previous IVF-related pregnancy loss?

Methods: This retrospective observational study included women who underwent vitrified blastocyst warming procedures, with or without trophectoderm biopsy for PGT-A, between January 2016 and June 2023. Participants had experienced two or more clinical pregnancy losses, with at least one loss following in vitro fertilization (IVF). The primary outcome was the cumulative live birth/ongoing pregnancy rate, analyzed using generalized estimating equations (GEE) with confounding adjustments.

Results: The cohort included 146 women, comprising 72 who intended to pursue PGT-A on thawed blastocysts (274 blastocysts) and 74 who proceeded directly to frozen embryo transfer (FET) without prior PGT-A (107 blastocysts). Fourteen women in the PGT-A group had no euploid embryos available for transfer. Among these, two patients had no warmed blastocysts suitable for testing, and twelve had all aneuploid embryoid. The cumulative live birth/ongoing pregnancy rate was significantly lower in the PGT-A group compared to the non-PGT-A group (34.7% [25/72] vs. 52.7% [39/74], adjusted odds ratio [AOR] 0.51, 95% confidence interval [CI]: 0.26-0.99, P = 0.048). Secondary outcomes, including live birth and pregnancy loss rates after initial FET, were comparable between the two groups. Among tested blastocysts, 58 (82.9%) had at least one euploid embryo, resulting in a euploidy rate of 48.6% (125/257).

Conclusions: PGT-A on cryopreserved unbiopsied blastocysts reduces cumulative live birth/ongoing pregnancy rates and could not improve pregnancy outcomes following the initial FET cycle in women with a history of IVF pregnancy loss.