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

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.