A Prospective Descriptive Study of Chromosomal Abnormalities in First Trimester Abortions

Introduction: Chromosomal abnormalities, particularly aneuploidies, are the leading cause of first trimester pregnancy loss, a common reproductive problem. Understanding these genetic factors is essential for counselling and management of affected couples.Objectives: To analyze chromosomal profiles of first trimester abortion cases and identify the most prevalent abnormalities causing miscarriage. Material & Methods: A prospective cytogenetic study was conducted on 122 first trimester abortion cases. Peripheral blood samples were processed for conventional karyotyping with Giemsa banding. Chromosomal anomalies were examined using a trinocular fluorescent microscope with Gene Asis software (Olympus BX53). Maternal age was recorded and correlated with outcomes. Results: Among 122 cases, 35.2% (n=43) showed abnormalities, while 64.7% (n=79) had normal karyotypes. Trisomy was most frequent (60.4%), with Trisomy 21 (42.3%), Trisomy 13 (34.6%), and Trisomy 16 (23.7%) predominating. Polyploidy (23.2%), Monosomy X (11.6%), and structural abnormalities (9.3%) were also detected. Abnormalities were more common in women ≥30 years, especially trisomies, whereas Monosomy X and polyploidy occurred more in younger women. Conclusion: Chromosomal abnormalities, particularly autosomal trisomies, are major causes of first trimester pregnancy loss and strongly correlate with maternal age. Incorporating cytogenetic testing into miscarriage evaluation, especially in recurrent cases, can aid reproductive planning. Advanced genomic tools may enhance diagnostic accuracy.