SCREENING AND GENETIC COUNSELING OF DOWN′S SYNDROME IN THE SECOND TRIMESTER OF PREGNANCY / 现代医院

ABSTRACT

Objective To investigate the clinical value of screening and genetic counseling of Down ′s syndrome in the second trimester of pregnancy for prevention of birth defects .Methods Fetal risk assessments were conducted by detecting concentration of alpha fetoprotein (AFP), free chorionic gonadotropin (Free-βHCG) and free female three alcohol (uE3) in maternal serum from pregnant women in the second trimester of pregnancy (14 ~20 +6 weeks) and combining with maternal age , weight, gestational weeks, ultrasonography (neck soft tissue thickness, NT) using a professional software.The high risk pregnant women had voluntary choice of amniocentesis for prenatal diagnosis after genetic counseling and informed consent , while regular follow -ups were done to those with low risks .Results Among 3 673 cases of pregnant women , 246 cases were at the high risk of DS , 17 cases of Trisomy 18 syndrome , 19 cases of Neural tube defects ( NTD) , with the positive rates of 6.7%, 0.46%, 0.52%, respectively .The total positive rate of pregnant women at the age of over 35 years was higher than those at the age of below 35 years old (p<0.01).Conclusion The screening of Down′s syndrome in mid trimester is a noninvasive method with high detection rate .There is important clinical value in prevention of birth defects , but we should do a good job about genetic counseling and interpretation in the process of screening and follow-up.