Presence of vacuoles in blastocysts is negatively associated with euploidy and live birth rates

Objective

To investigate whether the presence of vacuoles in biopsied blastocysts is associated with the likelihood of aneuploidy and clinical outcomes.

Subjects

This study retrospectively analyzed data obtained through preimplantation genetic testing for aneuploidy (PGT-A) performed on 3351 blastocysts from 826 patients at a single reproductive center between August 2018 and July 2020. Ultimately, 167 single euploid blastocyst transfers were performed in these patients. Vacuoles existing in the trophectoderm or inner cell mass were observed using blastocyst biopsy. After biopsy, all blastocysts were vitrified, and embryo transfer was performed in a subsequent treatment cycle.

Results

vacuole-negative

vacuole-positive

Of the 3351 blastocysts from 826 patients, 903 (26.9%) were discovered to have vacuoles. The vacuole-positive group had a significantly lower percentage of euploid blastocysts after TE biopsy than did the vacuole-negative group (28.8% vs. 35.5%; p < 0.001). Embryos with vacuoles were significantly more likely to be poor quality (30.6% vs. 18.2%, p < 0.001). Logistic regression analyses revealed that euploid blastocysts were positively associated with the absence of vacuoles, maternal age, and good embryo quality (vacuole-negative group: adjusted OR= 1.291, 95% CI = 1.089-1.530; age < 38 years: adjusted OR= 1.989, 95% CI = 1.692-2.337; good embryo quality: adjusted OR = 1.703, 95% CI = 1.405-2.064). The implantation rate and live birth rate were significantly lower for the transferred single euploid blastocysts with vacuoles than for the blastocysts without vacuoles (35.5% vs. 56.6%, p = 0.033; 29.0% vs. 52.2%, p = 0.020, respectively). The live birth rate was positively associated with the absence of vacuoles (adjusted OR = 2.792, 95% CI =1 1.180-6.608).

Conclusion

The formation of vacuoles in blastocysts is associated with lower rates of euploidy and live birth. Blastocysts without vacuoles should thus be prioritized for embryo transfer in in vitro fertilization cycles.

Keywords

vacuoles, blastocysts, euploidy rate, clinical outcomes, chromosomal abnormalities

Author: Lee, Yu-Jen, Ph.D.

Researcher of Genetic Diagnosis Laboratory, Lee Women's Hospital

Full text: Lee, Yu-Jen, et al. "Presence of vacuoles in blastocysts is negatively associated with euploidy and live birth rates." Fertility and Sterility (2023). DOI: https://doi.org/10.1016/j.fertnstert.2023.04.023P