Assessment of day-3 morphology and euploidy for individual chromosomes in embryos that develop to the blastocyst stage

Objective

To examine the relationship between day-3 morphology and euploidy for individual chromosomes in embryos that develop to the blastocyst stage by day 5.

Design

Retrospective cohort study.

Setting

Boston IVF, a large university-affiliated reproductive medicine practice.

Patient(s)

Ninety-nine patients undergoing their first preimplantation genetic screening (PGS) cycle between January 1 and December 31, 2006.

Intervention(s)

In vitro fertilization (IVF) and preimplantation genetic screening (PGS).

Main Outcome Measure(s)

Prevalence of euploidy for chromosomes X, Y, 8, 13, 14, 15, 16, 17, 18, 20, 21, and 22 in day-3 high implantation potential (HIP) versus non-HIP embryos that grew to day-5 blastocysts.

Result(s)

Seven hundred three embryos from 99 cycles in 99 patients underwent PGS. Three hundred sixty-four (52%) embryos from 88 cycles in 88 patients developed to the blastocyst stage by day 5. High implantation potential embryos were more likely to be euploid for chromosomes X/Y, 8, 15, 16, 18, and 22 compared with non-HIP embryos, with similar trends for chromosomes 14 and 17. There were no statistically significant differences between HIP and non-HIP embryos in euploidy prevalence for chromosomes 13, 20, and 21.

Conclusion(s)

Our data suggest that PGS may detect potentially viable but detrimental chromosomal abnormalities that are not detected by embryo morphology alone.

Key Words: Preimplantation genetic screening, embryo morphology, euploidy, aneuploidy, in vitro fertilization, assisted reproductive technology, ART outcomes