[Screening by maternal serum markers for Down's syndrome]

Abstract

Objective: To investigate the optimal method of screening for Down's syndrome (DS) with maternal serum mankers.

Methods: Screening by maternal serum markers for Down's syndrome was offered to all 2886 pregnant women in Peking Union Medical Hospital during 1996.11-2001.3. Alpha-fetoprotein (AFP), human chorionic gonadotrophin (free beta-HCG) were used as markers during the first year of pregnancy. Alpha-fetoprotein, free human chorionic gonadotrophin (HCG) and pregnancy-associated plasma protein A (PAPP-A) were used as mid pregnancy and first-trimester markers in next three years. Amniocentesis and (CVS) were done in those defined as risk cases.

Results: The detection rate of Down's syndrome by maternal serum markers was 3.8% (11/2886). The proportion of false positive results in group of triple markers (alpha FP, free beta-HCG, PAPP-A) was 5%.

Conclusions: The PAPP-A was a good marker to detect Down's syndrome in early pregnancy and may be used to predict the outcome during mid trimester of pregnancy. The AFP and free beta-HCG can be useful markers to detect Down's syndrome and fetal abnormality. While prenatal diagnostics can be shifted to an early pregnant period.