Embryo ploidy in vitrified versus fresh oocytes: Is there a difference?

Purpose: To evaluate embryo ploidy in a cohort of patients who underwent preimplantation genetic testing for aneuploidy (PGT-A) with vitrified oocytes compared to fresh oocytes.

Methods: Patients who underwent their first autologous oocyte vitrification and warming followed by in vitro fertilization (IVF) and trophectoderm biopsy for PGT-A between 1/1/2017 and 12/31/2021 at a single academic institution were included. Patients were compared 1:3 to age-matched controls who underwent their first IVF cycle with fresh oocytes and subsequent trophectoderm biopsy for PGT-A. The primary outcome was the proportions of euploid, mosaic, and aneuploid embryos between those using vitrified versus fresh oocytes.

Results: 117 patients who cryopreserved a total of 1,272 mature oocytes were included in the study and were matched with 351 controls using fresh oocytes. The average age was 36.9 ± 2.6 years, and the median interval between oocyte vitrification and warming was 38 months. There were similar numbers of mature oocytes (10.9 ± 4.9 vs. 11.1 ± 6.3, P = .67), fertilized oocytes (7.8 ± 4.0 vs. 8.7 ± 5.5, P = .10), and blastocysts per patient (5.1 ± 3.1 vs. 5.8 ± 4.3, P = .10) between those using vitrified versus fresh oocytes. In terms of embryo ploidy results, there were no statistically significant differences in rates of euploidy (40.1% vs. 41.6%), mosaicism (15.7% vs. 12.0%), or aneuploidy (44.3% vs. 46.4%) (P = .06) between the two groups.

Conclusions: Oocyte vitrification with subsequent warming, fertilization, and trophectoderm biopsy for PGT-A was not associated with adverse chromosomal competence when compared to age-matched controls utilizing fresh oocytes.