Analysis of Umbilical Vein Circulation in Normal Fetus at 20–24 Weeks by Doppler Ultrasonography

The umbilical vein supplies blood flow from the placenta to the carcass with high oxygen content, shouldering the nutrients needed for the fetus to grow and develop. Umbilical artery (UMA) is vein blood, and fetal metabolites are transported to the mother and excreted. The development of umbilical veins and umbilical arteries is directly related to the fetus growth and fetal survival. Ultrasound measurements of 20–24 weeks of pregnancy and left portal vein blood flow (QLPV) were calculated from the infarcted placenta insertion point, 50 mm from the umbilical cord. Color Doppler flow imaging (CDFI) was used to monitor the changes of fetal umbilical vein blood flow, blood flow velocity, umbilical artery diastolic components, and the effects of normal umbilical artery and vein blood flow dynamics at 20–24 weeks, reflecting fetal-placental blood circulation function status. Two issues were solved in this work: (1) the effects of placenta blood pool on the fetal umbilical vein circulation; (2) the size determination of the large blood pool. Last, the pathogenesis of spontaneous abortion before pregnancy was explored, providing a way to cure such cases.