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

Abstract

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

Design: Retrospective observational study.

Setting: A single reproductive center.

Intervention(s): None.

Patient(s): This study retrospectively analyzed data obtained through preimplantation genetic testing for aneuploidy 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 the biopsy, all blastocysts were vitrified, and embryo transfer was performed in a subsequent treatment cycle.

Main outcome measure(s): The associations between vacuoles and euploidy or live birth rates were assessed using logistic regression models and estimated adjusted odds ratios (ORs) and 95% confidence intervals (CIs).

Result(s): 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 the vacuole-negative group (28.8% vs. 35.5%). Embryos with vacuoles were significantly more likely to be poor quality (30.6% vs. 18.2%). 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 and live birth rates were significantly lower for the transferred single euploid blastocysts with vacuoles than those without (35.5% vs. 56.6%; 29.0% vs. 52.2%, respectively). The live birth rate was positively associated with the absence of vacuoles (adjusted OR 2.792; 95% CI: 1.180-6.608).

Conclusion(s): 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 vitro fertilization cycles.

Keywords: Vacuoles; blastocysts; chromosomal abnormalities; clinical outcomes; euploidy rate.