Does slow embryo development predict a high aneuploidy rate on trophectoderm biopsy?

Area of Science:

• Reproductive Science
• Genetics
• In Vitro Fertilization (IVF)

Background:

• Aneuploidy, an abnormal chromosome number, is a major cause of implantation failure and miscarriage in IVF.
• Blastocyst biopsy timing (day 5 vs. day 6) may influence aneuploidy detection rates.

Purpose of the Study:

• To compare aneuploidy rates in expanded blastocysts biopsied on day 5 versus day 6 of development.
• To assess the impact of maternal age on aneuploidy rates in relation to biopsy timing.

Main Methods:

• Array comparative genomic hybridization (aCGH) was used to analyze 1171 blastocysts from 465 IVF patients.
• Embryo biopsy was performed on day 5, day 6, or both, at the expanded blastocyst stage.

Main Results:

• Day 6 blastocysts exhibited a higher aneuploidy rate (69.9%) compared to day 5 (61.4%).
• Aneuploidy rates increased with maternal age, but this was not influenced by biopsy day.
• No significant differences were found in aneuploidy types (single, double, complex) based on biopsy day.

Conclusions:

• While day 6 biopsy reveals higher aneuploidy, euploid embryos from both days yield similar successful gestation rates.
• Biopsy timing does not alter the impact of maternal age on aneuploidy.
• These findings aid in optimizing IVF protocols and genetic screening strategies.