The difference between Down's screening and four-dimensional

Down's screening is a blood test taken from pregnant women during the 15-20 weeks of pregnancy. It can comprehensively analyze and judge whether the fetus has congenital genetic problems according to the gestational age and weight of pregnant women, and accurately judge whether trisomy 21 syndrome and trisomy 18 syndrome are abnormal. Do four-dimensional examination is to do four-dimensional color ultrasound to determine whether the fetus has congenital malformations, this examination can only check whether there is cleft lip and palate, heart malformation, kidney malformation, or brain development abnormalities in the process of fetal growth, this is after examination of the surface symptoms, Down's screening is to detect genetic problems. Do four-dimensional examination needs to be done during the 22-26 weeks of pregnancy, these two kinds of examination are different.