Chromosomal abnormalities in the first and second polar body

Area of Science:

• Reproductive biology
• Genetics
• Assisted reproductive technology

Background:

• Aneuploidy in oocytes is a major cause of infertility and miscarriage.
• Advanced maternal age is associated with increased oocyte aneuploidy rates.
• Pre-implantation genetic testing aims to improve IVF success rates.

Purpose of the Study:

• To evaluate the efficacy of polar body testing for aneuploidy screening in oocytes from women of advanced maternal age undergoing IVF.
• To determine the contribution of meiotic errors to aneuploidy in oocytes.
• To assess the impact of polar body testing on clinical pregnancy rates.

Main Methods:

• Polar body sampling from 5590 oocytes across 917 IVF cycles.
• Fluorescence in situ hybridization (FISH) analysis for chromosomes 13, 16, 18, 21, and 22.
• Correlation of polar body testing results with clinical pregnancy outcomes.

Main Results:

• FISH results were obtained for 82.2% of oocytes, with 45.2% identified as aneuploid.
• 36.1% of aneuploidies originated from the first meiotic division, and 29.3% from the second.
• Transfer of 2520 aneuploidy-free oocytes resulted in 182 clinical pregnancies (22.2%) and 140 live births.

Conclusions:

• Polar body testing is a viable method for pre-selecting aneuploidy-free oocytes.
• This approach can enhance pregnancy rates in IVF patients, particularly those of advanced maternal age.
• Understanding meiotic error origins aids in improving oocyte quality and IVF outcomes.