Chromosomal abnormalities in the first and second polar body

Abstract

Aneuploidy free oocytes may be pre-selected by testing the first and second polar bodies removed from oocytes following their maturation and fertilization. We present here our experience on the application of the method in IVF cycles from patients of advanced maternal age. Overall, 5590 oocytes were obtained from 917 cycles and tested by polar body sampling and fluorescent in situ hybridization (FISH) analysis using specific probes for chromosomes 13,16,18,21 and 22. FISH results were available in 4599 (82.2%) of 5590 oocytes studied, from which 2077(45.2%) were with aneuploidies. Thirty six point one percent of aneuploidies were of the first meiotic origin, and 29.3% of the second meiotic origin. Most errors in the first meiotic division were represented by chromatid errors. The transfer of embryos deriving from 2014 of 2520 aneuploidy free oocytes in 821 treatment cycles resulted in 182 (22.2%) clinical pregnancies and 140 healthy children born after confirmation of the polar body diagnosis. Polar body testing of oocytes provides an approach for pre-selection of aneuploidy free embryos, improving pregnancy rate in IVF patents of advanced maternal age.