Use of array comparative genomic hybridization (array-CGH) for embryo assessment: clinical results

Abstract

Objective: To review clinical outcomes after preimplantation genetic screening. Most methods of embryo viability assessment involve morphologic evaluation at different preimplantation developmental stages. A weak association between blastocyst morphology and aneuploidy has been described, supporting the basis for preimplantation genetic screening (PGS) for assessment of embryo viability. The expected improvement in reproductive outcome rates has been reached with the application of microarrays based on comparative genomic hybridization (CGH) in clinical routine PGS.

Design: Review of published studies and own unpublished data.

Setting: University-affiliated private institution.

Patient(s): IVF patients undergoing PGS at different stages.

Intervention(s): PGS with polar body, cleavage-stage, and blastocyst biopsies.

Main outcome measure(s): Aneuploidy, implantation, and pregnancy rates.

Results: The clinical outcome after analysis of all 24 chromosomes improved pregnancy and implantation rates for different indications to a higher degree than the previously available technology, fluorescence in situ hybridization (FISH), in which only a limited number of chromosomes could be analyzed.

Conclusion(s): Most of the data regarding the controversy of day-3 biopsy come from FISH cycles, and the utility of day-3 biopsy with new array-CGH technology should be further evaluated through randomized controlled trials. The current trend is blastocyst biopsy with a fresh transfer or vitrification for transfer in a nonstimulated cycle.