Female Reproductive Ageing and Chromosomal Abnormalities in a Large Series of Women Undergoing IVF.

Chromosomal abnormalities are often detected in women with reproductive problems. This study aimed to investigate the presence and type of chromosomal aberrations in peripheral blood of women undergoing in vitro fertilization (IVF) and their possible association with advanced maternal age (AMA). A total of 1,837 women undergoing IVF between 2016 and 2019 were enrolled in the study. Women were further divided in AMA (≥35 years) and younger women (<35 years). Chromosomal abnormalities were detected by peripheral blood karyotyping using standard cytogenetic techniques. Chromosomal abnormalities were detected in 13.5% of the enrolled women; 1.1% had autosomal abnormalities including reciprocal translocations, inversions, Robertsonian translocations, and a supernumerary marker chromosome, while 12.4% had X chromosome abnormalities. The frequency of chromosomal abnormalities was significantly higher in AMA women than in younger ones (17.4% vs. 3.9%, p < 0.05). Women of AMA exhibited X chromosome mosaicism with a frequency of 16.1%, and mosaic karyotypes with 2 and 3 aneuploid cell lines were more frequently detected. X chromosome mosaicism is the most common karyotypic aberration in women undergoing IVF and has 6-fold increased incidence in AMA women compared to younger ones. The present study verifies previous observations that low-level peripheral blood X chromosome mosaicism and the number of aneuploid cell lines observed in women of AMA could be an indication of aneuploidy and poor quality of oocytes contributing to infertility.