Screening analysis of Down syndromes in 10484 cases on middle period pregnancy

Objective:Screening middle period samples of serum of pregnant women to diagnose chromosome diseases and nervous tube defects of fetus so that birth defects rate can be decreased. Methods and Results: DELFLA Eu and Sm double marker reagents are used to test the concentrations of AFP and β-HCG in the serum of middle period pregnant women. The morbidities of Down syndromes (DS) and nervous tube defect (NTD) are calculated based on the testing results with supported software,taken such factors as the age,weight,number of fetus,diabetes and smoking experiences of the pregnant women into consideration. The calculated results show that 1146 cases are of high risks in 10484 test samples,with a positive rate of 10.93%. Among the high risk cases,1059 cases indicate DS,34 cases suggest 18-Ⅲ,and 53 cases are NTD. Prenatal diagnosis is carried out for 506 cases (47.29%),including amniocentesis and umbilical cell culture. After-birth visit on the high-risk pregnant women screened before the date of 2007-6-30 indicated that 9 births suffered DS (including 2 fail-to-diagnosed cases). The morbidity of DS is 0.86‰ (9/10484). 7 cases suffered other chromosome abnormity. The total chromosome abnormity incidence is 1.53‰ (16/10484). 38 cases are found with fetus malformation,death and dysplasia. Conclusion: The results in this paper indicate that screening of middle period serum of pregnant women is necessary in lowering the risk of DS incidence. However,better results can only be obtained by combining multiple test methods and clinical behaviors in order to decrease the rate of birth defects.