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

Area of Science:

• Reproductive Medicine
• Genetics
• Embryology

Background:

• Embryo viability assessment traditionally relies on morphology, which has a weak association with aneuploidy.
• Preimplantation genetic screening (PGS) is based on the principle of assessing embryo viability.
• Microarray-based comparative genomic hybridization (aCGH) has been applied in routine PGS.

Purpose of the Study:

• To review clinical outcomes following preimplantation genetic screening.
• To evaluate the effectiveness of different PGS methods.

Main Methods:

• Review of published studies and unpublished data.
• Analysis of IVF patients undergoing PGS at various stages (polar body, cleavage-stage, blastocyst biopsy).
• Comparison of aneuploidy, implantation, and pregnancy rates.

Main Results:

• Analysis of all 24 chromosomes via aCGH improved pregnancy and implantation rates compared to fluorescence in situ hybridization (FISH).
• FISH technology could only analyze a limited number of chromosomes, leading to less comprehensive screening.
• aCGH demonstrates superior clinical outcomes in PGS.

Conclusions:

• Day-3 biopsy utility with aCGH requires further evaluation via randomized controlled trials, as current data often stems from FISH cycles.
• The current trend favors blastocyst biopsy, with fresh or vitrified transfer in a nonstimulated cycle.
• Advanced PGS techniques like aCGH are crucial for improving IVF success rates.