Study on Down's syndrome prenatal screening and diagnosis

Objective:To investigate the value of screening and diagnosing Down's syndrome for the frequency of natal defect. Methods:Autotime resolved fluoroimmunoassay system was used to detect the maternal serum AFP and free-β-HCG in 68813 pregnant women at about 15～20 weeks of gestation. Down's syndrome,NTD,Edwards syndrome risk value was calculated with Multicalc software,their cut off were 1∶270,1∶250,1∶350 separately. The pregnant women whose value are higher than or equal to cut-off would be at high risk and need to exclude fetal abnormal karyotype coming diagnoses with ultrasound examination,amniocentesis or fetal blood. Results:68813 pregnant women accepted antenatal screening,2632 of them were at high risk with Down's syndrome or trip loid syndrome,542 case with NTD. In the high risk pregnant women,67 case with fetal abnormal chromosome were found by amniotic fluid or fetal blood culture,58 case with abnormal fetal were found by ultrasound. Conclusion:Prenatal screening and prenatal diagnosis have very important significance to the prevention of Down's syndrome and other congenital abnormality.