Objective:To assess the value and impact of screening programme in mid-pregnancy women for the congenital fet abnormality that uses the two maternal serum markers:α-fetoprotein(AFP)and freeβhuman chorionic gonadotrophin(free-βHCG) Methods:Serum screening of AFP and free-βHCG were offered to the 14～20 weeks pregnant Measuring the serum AFP and free βHCGin pregnant women with ELISA

and combined with other factors:age

weeks of pregnancy

weight

etc.Measuring the high ri rate with special software.Results:Within 1 648 cases of women in the mid-pregnancy

Down’s syndrom

18-trisomysyndrome an neural tube defect high risk rates in screen were 7.16%

0.61%and 2.37%respectively.1 case was confirm the Down’s syndrome analysis of cytogenetics

another 2 cases was diagnosed neural tube defect via ultrasonography.Conclusion:the second trimester doub test would be effective and safe screening strategies and could be used to decrease natality of congenital fetal malformation