Preimplantation genetic testing laboratory classification strategies are associated with diagnostic yield and downstream clinical performance.

Abstract

Objective: To evaluate whether PGT-A laboratory was associated with diagnostic yield and live birth per single euploid embryo transfer.

Design: Retrospective cohort study.

Subjects: We analyzed a total of 9,630 PGT-A cycles performed between January 2015 and December 2023, comprising 40,308 blastocysts tested using trophectoderm biopsy and next generation sequencing. Three commercial PGT-A laboratories were utilized: Laboratory A (n = 18,480), Laboratory B (n = 19,261), and Laboratory C (n = 2,567). Clinical outcome analyses were restricted to 7,333 single euploid embryo transfers performed at the network's main clinic.

Exposure: PGT-A laboratory.

Main outcome measures: Euploidy rate, likelihood of having at least one euploid embryo available for transfer, and live birth rate per single euploid embryo transfer.

Results: Overall, 52.3% (21,093/40,308) of blastocysts were diagnosed as euploid. Diagnostic yield differed between laboratories and varied according to maternal age. Compared with Laboratory A, Laboratory B had lower euploidy rates and a lower likelihood of obtaining at least one euploid embryo in younger patients, with higher euploidy rates observed among patients aged >42 years. Laboratory C had a consistently lower diagnostic yield in patients younger than 41 years. Among 7,333 single euploid embryo transfers performed at the main clinic, live birth rates per transfer were 49.8%, 41.6%, and 50.7% for Laboratories A, B, and C, respectively. After adjusting for maternal age, BMI, infertility indication, endometrial preparation and thickness, embryo grade, and biopsy day, Laboratory B remained associated with lower odds of live birth per single euploid embryo transfer compared to Laboratory A (OR=0.71, [95%CI: 0.64-0.79]; p<0.001), while Laboratory C was comparable (OR=1.08, [95%CI: 0.89-1.32]; p=0.418).

Conclusion: PGT-A laboratory classification strategy was associated with both diagnostic yield and live birth per transfer. The discordance between these outcomes shows that euploidy rates alone do not provide a complete measure of laboratory performance and should be interpreted alongside downstream clinical outcomes.