A novel method for the detection of Down syndrome with the use of four serum markers.

Abstract

The purpose of this study was to evaluate the use of the Lens culinaris agglutinin-reactive alpha-fetoprotein ratio for the detection of fetal Down syndrome in combination with traditional serum markers. We obtained maternal serum from 530 women with unaffected pregnancies and 31 women who were pregnant with a fetus with Down syndrome at 14 to 20 weeks of gestation. Various combinations of Lens culinaris agglutinin-reactive alpha-fetoprotein ratio, alpha-fetoprotein, human chorionic gonadotropin, and unconjugated estriol were evaluated by score, without regard for the maternal age-related fetal Down syndrome risk. The best combination of serum markers, according to our scoring method, was a combination of all 4 markers. This combination showed a sensitivity of 83.9%, with a 5.1% false-positive rate for Down syndrome. Moreover, in older women, high sensitivity was obtained without increasing the false-positive rate. The screen using all 4 markers showed high sensitivity in all age groups without increasing the false-positive rate.