Investigation on 36947 fetuses with congenital defects in prenatal screening of maternal blood of pregnant women in the second trimester pregnancy

Objective:To explore the function of alpha fetoprotein(AFP)and free human chorionic gonadotropin(Free-β-hCG)in screening of fetal congenital defects.Methods:The serum levels of AFP and Free-β-hCG in pregnant women of 15～20 gestational weeks were detected,then the risk ratio was calculated on prenatal screening software according to maternal age,gestational weeks,maternal weight,history of pregnancy,diabetes or not and smoking;the pregnant women with high risk received chromosomal examination of amniotic fluid cells and type B ultrasonography;all the pregnant women were followed up till delivery.Results:Among 36 947 pregnant women,13,6 and 3 pregnant women were diagnosed as Down's syndrome,18 trisomy syndrome and other abnormal chromosome karyotypes,respectively.Conclusion:The joint detection of AFP and Free-β-hCG can be used to screen fetal congenital defects with safety and feasibility,which may reduce the birth rate of fetus with congenital defects effectively.