Day-3 embryo morphology predicts euploidy among older subjects

Area of Science:

• Reproductive Medicine
• Embryology
• Genetics

Background:

• Assessing embryo viability is crucial in in vitro fertilization (IVF).
• Preimplantation genetic diagnosis (PGD) is used to screen embryos for chromosomal abnormalities.
• Day-3 embryo morphology is a traditional method for embryo assessment.

Purpose of the Study:

• To determine if day-3 embryo morphology can predict euploidy.
• To evaluate the effectiveness of embryo morphology in different maternal age groups.

Main Methods:

• Retrospective study of 144 subjects undergoing IVF and PGD.
• Day-3 embryo characteristics were standardized into a score.
• Morphology scores were compared with PGD fluorescence in situ hybridization results for key chromosomes.

Main Results:

• 67% of biopsied blastomeres were chromosomally abnormal.
• Advanced maternal age (AMA) was associated with a higher likelihood of chromosomal errors.
• Morphology predicted PGD results in AMA subjects, but not in younger women.
• Cellular fragmentation predicted euploidy in both age groups, while cell number did not.

Conclusions:

• Day-3 embryo morphology aids in selecting euploid embryos for AMA subjects.
• Other factors may cause embryo dysmorphism in younger women.
• Cellular fragmentation is a sensitive indicator of chromosomally normal embryos across age groups.
• The superiority of PGD over standard day-3 embryo assessment for embryo selection remains unclear, especially for AMA women.