Maternal serum screening for down syndrome by using alpha-fetoprotein and human chorionic gonadotropin in an asian population. a prospective study

The purpose of the present study is to evaluate the efficacy of second-trimester maternal serum screening program by using alpha-fetoprotein (AFP) and total human chorionic gonadotropin (hCG) in an Asian population. During June 1994 to July 1998, we conducted a prospective study of serum screening protocol for Down syndrome. The cut-off point for a positive result in this analysis was a risk of >/=1/270. A total of 17,742 pregnant women with singleton pregnancy were screened, and 1,153 (6.5%) had positive result. Sixteen of the 17,742 pregnancies had Down syndrome, and 10 of them had positive result. The positive rate and detective rate for Down syndrome were 6.5 and 62.5%, respectively. However, the detective rate will reduce to 47.6% after being adjusted by age-specific risk. It is indicated that the double-marker test using AFP and total hCG is an effective screen strategy for second-trimester detection of Down syndrome in Asian women.