Triple marker screening for fetal chromosomal abnormalities in Korean women of advanced maternal age

The purpose of this article is to assess the value of maternal serum triple marker screening of alpha-fetoprotein (AFP), human chorionic gonadotropin (hCG), and unconjugated estriol (uE(3)) for the prenatal diagnosis of fetal chromosomal abnormalities in Korean women of advanced maternal age. Matern al sera were collected from 458 pregnant Korean women aged 35 between 15 an d 20 weeks gestation before amniocentesis. A patient- specific second trime ster risk for fetal Down's syndrome was calculated using the median values for AFP, hCG, uE(3) and maternal age. Twelve fetal chromosomal abnormalitie s were identified. These included six cases of trisomy 21, one case of 46,X Y/47,XY,+21, two cases of trisomy 18, one case of trisomy 13, and two cases of 45, X. A cutoff level of 1:200 detected 85.7% (6/7) of the cases of Dow n's syndrome and 20% (1/5) of the other aneuploidies, with a 27.3% false po sitive rate. However, a cutoff level of 1:270 did not result in any gains i n detecting Down's syndrome or other aneuploidies at the expense of a false positive rate of 34.3%, Second trimester triple marker resting is an effec tive screening tool for detecting fetal Down's syndrome in Korean women gre ater than or equal to 35 years old. However, it is not an effective screeni ng tool for non-Down's chromosomal abnormalities.