[Ultrasound diagnosis of left inferior vena cava and double inferior vena cava in fetus].

To evaluate the application of ultrasonography in prenatal diagnosis of left inferior vena cava and double inferior vena cava in fetus. The clinical data and ultrasonographic findings of the fetuses with left inferior vena cava (18 cases) or double inferior vena cava (16 cases) were retrospectively analyzed. The ultrasonographic images of left inferior vena cava showed that in the transverse view of the fetal upper abdomen the inferior vena cava and abdominal aorta were in the normal position; below the level of the hilum, the inferior vena cava was located behind the left side of the abdominal aorta; at the level of the hilum, it crossed the front of the abdominal aorta and run diagonally to the upper right, forming the right inferior vena cava and finally entered into the right atrium. The ultrasonographic images of double inferior vena cava showed that in the transverse view of the fetal lower abdomen, in front of spine there were three transections of blood vessels; in coronal plane of abdomen, the veins run on both sides of the abdominal aorta and entered to the iliac vein of the same side. In 34 cases of abnormal inferior vena cava, there were 17 cases complicated with other system abnormalities, including 13 cases of cardiac anomalies. The left inferior vena cava and double inferior vena cava have characteristic imaging findings, and prenatal diagnosis can be made with ultrasonography. This type of congenital deformity is frequently complicated with other system abnormalities, which should be excluded in fetus, especially for heart system.