Prenatal Screening of Cytogenetic Anomalies -A Ten Year Retrospective Study on 1510 Cases

Abstract

Introduction: Prenatal diagnostic is a diagnostic method which is used to prove the presence of chromosome changes, a large number of metabolic disorders and other morphological fetus abnormalities. Prenatal genetic testing mostly refers to the molecular genetic and cytogenetic methods used during pregnancy to diagnose genetic fetal conditions. Aim: To investigate the existence and incidence of cytogenetics abnormalities in fetuses. Material and Methods: The retrospective research is based on cytogenetic analysis of the 1510 amniotic fluid samples collected from pregnant women sent to the cytogenetic laboratory from January, 2012 to December, 2022. Results: The karyotype without visible structural and numerical changes was detected in 96.8% (1462/1510) cases. The fetal karyotype was abnormal in 3.2 % (48/1510) of the cases. Trisomy 21 was the most frequent chromosome aberration detected in 1.12% (17/1510) cases followed by pericentric inversion 9 (10/1510; 0.66%) and trisomy 18 (4/1510; 0.26%). Mosaics were detected in five cases (5/1510; 0.33%). Comparing the prevalence of chromosome abnormalities according to maternal age, we come to know the prevalence of chromosome aberrations in the group of females above age 35 (26/790; 17.2/1000) is higher than in the group of females under age 25 (7/95; 4.63/1000), but not significantly different (P= 0.09). Conclusion: Conventional cytogenetics maintains its role as a powerful diagnostic tool in detecting chromosomal changes during prenatal screening.