Chromosomal aberrations, such as whole-chromosome aneuploidies (WCA), segmental aneuploidies (SA), whole-chromosome mosaicism (WCM), and segmental mosaicism (SM), are key factors influencing embryonic development and the outcomes of fertility programs. This analytic review critically examines the prevalence and origins of these genetic abnormalities, emphasizing the significant maternal contribution to WCA and the age-related nature of these aberrations. In contrast, SA, WCM, and SM appear largely age-independent and show considerable variability across studies, mainly due to technical artifacts and methodological differences. By analyzing the accumulated data, scrutinizing methodological discrepancies in preimplantation genetic testing for aneuploidies (PGT-A), and distinguishing between biological phenomena and artifacts, this review aims to clarify the current understanding of chromosomal aberrations in human embryos and their impact on reproductive health.