Chromosome analysis in embryos from young patients with previous parity

Area of Science:

• Reproductive Medicine
• Human Genetics
• Embryology

Background:

• Preimplantation genetic screening (PGS) is utilized for family balancing.
• Embryo viability and implantation success are critical in assisted reproductive technologies.
• The accuracy of fluorescence in-situ hybridization (FISH) in assessing chromosomal normality requires further validation.

Purpose of the Study:

• To investigate the correlation between chromosomal abnormalities and embryo viability.
• To determine the sensitivity and false-negative rate of FISH for specific chromosomes (13, 16, 18, 21, 22).
• To evaluate the predictive power of embryo morphology versus chromosomal analysis for implantation success.

Main Methods:

• Retrospective analysis of 173 couples undergoing PGS for X and Y chromosomes.
• Re-analysis of transferred blastomeres using FISH for chromosomes 13, 16, 18, 21, 22.
• Comparison of euploid embryo rates between pregnant and non-pregnant women.

Main Results:

• A significantly lower proportion of euploid embryos was observed in non-pregnant women (49%) compared to those with term pregnancies (75%) (P < 0.001).
• In 21 non-pregnant patients, all transferred embryos were chromosomally abnormal.
• The FISH analysis yielded a false-negative rate of 4.0% per patient and 1.9% per embryo.

Conclusions:

• Chromosomal abnormalities are a significant factor in early embryo demise and implantation failure.
• Embryo morphology has limited predictive power for implantation success.
• FISH analysis, while valuable, has a measurable false-negative rate that should be considered in clinical practice.