Studies of prenatal screening and diagnosis in Down′s syndrome and NTD.

Objective:To establish a rapid and accurate method to screen and diagnose Down′s syndrome and other congenital abnormality and finally reduce the frequency of natal defect.Methods:The value of AFP and β-HCG in the serum of 30722 pregnant women at about 14th~20th weeks gestation were detected by ELISA and with professional software YOUSHENG SHENGSUAN,their risk coefficient were calculated.For the Down′s syndrome high risk pregnant women,karyotypes in amniotic fluid were analyzed and gene diagnosis were carried out.For neural tube defect(NTD) high risk cases,B-ultrasonography was performed.Results:In 30722 pregnant women,1806 cases(5.88%) were detected for abnormal pregnancy,of which 1434 cases(4.7%) were high risk for Down′s syndrome,262 cases were NTD and 110 cases were trisomy 18 or trisomy 13.In the 785 cases who wanted to be further diagnosed,22 cases were trisomy 21,1 case was 46,XX,5p-,and 3 cases were trisomy 18.Although 110 trisomy 18 or trisomy 13 high risk cases didn′t accept further diagnosis,3 cases of them were certified to be abnormal pregnancies because the fetuses died in the womb.According to B-ultrasonography detection,5 of 262 NTD high risk cases were NTD fetus.Conclusion:Prenatal screening and prenatal diagnosis play an important role in preventing the birth of Down′s syndrome and other congenital abnormalities.