To determine whether there is any problem with the fetal urinary system, it can be detected by ultrasound in early pregnancy, and can be determined by amniotic fluid in the middle or late pregnancy. The common manifestations of fetal urinary system malformation are unilateral kidney, renal hypoplasia and so on. To determine whether there is any problem with the fetal urinary system, you can check whether there is any kidney development abnormality through color ultrasound in the early stage. In the mid-pregnancy and late pregnancy, because the amniotic fluid is mainly produced by the fetus urination, if the fetus has a malformation of the urinary system, its kidneys can not urinate can make the amniotic fluid volume significantly reduced, so you can use the amniotic fluid volume to initially determine whether the fetus has a malformation of the urinary system. It is recommended that pregnant women do regular checkups during pregnancy, relax, avoid excessive anxiety, and consult a doctor in time when they encounter abnormalities.