Transfer of embryos with segmental mosaicism is associated with a significant reduction in live-birth rate
Transfer of segmental mosaic compared with euploid embryos results in a reduced live birth.
Volume 111, Issue 1, Pages 69–76
Temeka Zore, M.D., Lindsay L. Kroener, M.D., Chunmin Wang, Ph.D., Lian Liu, M.D., Richard Buyalos, M.D., Gary Hubert, M.D., Mousa Shamonki, M.D.
To evaluate the impact of segmental mosaicism on pregnancy outcomes from the transfer of embryos previously designated as euploid.
Retrospective cohort analysis.
Single, private, high-volume fertility center.
Three hundred and twenty-seven women who underwent 377 frozen single euploid embryo transfers.
Trophectoderm biopsy of embryos cultured to the blastocyst stage, where all transferred embryos were designated euploid by high-density oligonucleotide array comparative genomic hybridization (aCGH); after ascertaining all outcomes, revaluation of aCGH results for evidence of segmental mosaicism (defined as mosaicism on a portion of a chromosome).
Main Outcome Measure(s)
Live-birth rate and spontaneous abortion rate.
Of the 377 embryos transferred, 357 were euploid with no mosaicism, and 20 embryos had segmental mosaicism. Segmental mosaics had a statistically significantly lower live-birth rate compared with euploid controls (30.0% vs. 53.8%). When controlling for age and day of Trophectoderm biopsy, the odds for live birth after transfer of segmental mosaics were reduced by 66% compared with euploid controls (0.34; 95% confidence interval, 0.13–0.92). The spontaneous abortion rate was statistically significantly higher after transfer of segmental mosaics compared with euploid controls (40.0% vs. 18.2%).
Blastocysts with segmental mosaicism have reduced reproductive potential but retain the ability to result in live birth. These results support reporting segmental mosaicism to optimize selection of a single embryo for transfer that will maximize the chance of life birth.