AIM: The purpose of this article was to evaluate the reliability of maternal 
serum triple marker screening of alpha-fetoprotein, human chorionic 
gonadotropin, and unconjugated estriol for the prenatal diagnosis of fetal 
chromosomal abnormalities in Turkish pregnant women.
METHOD: Medical records were used to analyze indications of amniocentesis and 
quantitative fluorescent-polymerase chain reaction. Anomaly screening was 
performed for all patients between 13 and 22 weeks of pregnancy. A total of 1725 
pregnancies with chromosomal abnormality risk according to triple test screening 
were accepted for fetal chromosome analysis and quantitative 
fluorescent-polymerase chain reaction.
RESULTS: Chromosomal aberrations were observed in 56 (3.2%) cases. About 44.6% 
of the abnormalities detected were numerical aberrations; however, 55.3% of the 
abnormalities were structural aberrations. Abnormalities detected were inversion 
of chromosome 9 in 20 cases, trisomy 21 in 14 cases, 46,XX/47,XX, +21 in 1 case, 
trisomy 18 in 2 cases, trisomy 13 in 1 case, 47,XXY, in 1 case, 45,X, in 1 case, 
structural abnormalities in 12 cases, and mosaic or tetraploidy in 6 cases.
CONCLUSION: Second trimester triple test is an effective screening tool for 
detecting fetal Down syndrome in Turkish women.