Abstract: Prenatal screening is the secondary prevention which aims to prevent birth-defect，thus a routine prenatal screening programme is necessary for pregnant women. The prenatal screening programme includes serological screening for Down′s syndrome and NTD during the 1st and 2nd trimester，molecular biology screening and diagnosis for thalassemia disease，and prenatal sonographic diagnosis of any defects in fetus′ body surface，organs and skeleton as well as congenital diseases to identify the high-risk population. The screening programme is based on genetic factors to select the optimal period for prenatal diagnosis in order to enhance the detection rate for congenital defect and genetic disorder， strengthen the quality control and management of high-risk population，and develop predictive clinical intervention for adverse pregnancy outcomes. The ultimate goal of prenatal screening programme is to reduce birth- defect rate and to improve population′s quality.

Key words: Prenatal diagnosis, Congenital abnormalities, Down syndrome, Thalassemia, Quality control