Can a fetus with right umbilical vein be kept?

The right umbilical vein is a type of malformation, also called persistent right umbilical vein. When this happens, symptomatic analysis is required. Generally, it will not lead to fetal malformations. For such fetuses, there will be no health problems after birth. However, it is important to understand and be vigilant that a small number of fetuses may have fetal malformations, such as hydrocephalus, single umbilical artery, etc.

Can a fetus with right umbilical vein be kept?

By the end of the fourth week of the embryo, there are two umbilical veins, one on the left and one on the right, which are directly connected to the venous sinus. Later, the umbilical vein anastomoses with the hepatic sinusoids and loses its connection with the venous sinus. The growth and development of the fetal liver causes the umbilical veins in the liver to become entangled, knotted, and eventually degenerate. However, the left umbilical vein does not degenerate, but instead concentrates all the venous blood returning from the placenta to the fetus. When the left umbilical vein connects to the left branch of the portal vein and enters the liver, part of the blood enters the right liver through the right branch of the portal vein, and most of the blood returns directly to the inferior vena cava and right atrium through the ductus venosus.

If the right umbilical vein does not degenerate, but the left umbilical vein degenerates, at this time, the right umbilical vein enters the liver and then enters the left liver lobe through the anastomotic branch. At the same time, it is directly connected to the ductus venosus, thus forming a persistent right umbilical vein. The reasons for this process are unclear. In rare cases, the right umbilical vein may pass through the liver and directly connect to the inferior vena cava or right atrium, causing hemodynamic abnormalities.

Most cases of persistent right umbilical vein malformation are associated with fetal malformation

Only a few may be accompanied by fetal malformations, such as hydrocephalus, single umbilical artery, short limbs, atrial septal defect, ventricular septal defect, aortic coarctation, tracheoesophageal fistula, hypospadias, renal displacement, situs inversus, intestinal rotation abnormalities, and imperforate anus. If the right umbilical vein is directly connected to the inferior vena cava or right atrium, or even the iliac vein, the sonogram will not show that the umbilical vein is connected to the ductus venosus in the liver, and the ductus venosus is absent. Careful tracking of the umbilical vein can reveal abnormal connection sites, and color Doppler ultrasound can assist in diagnosis. This situation is often accompanied by multiple malformations, such as atrioventricular channel, arrhythmia, single umbilical artery, hydronephrosis, renal agenesis, choroidal cyst, pleural effusion, hemi-cone, finger and toe abnormalities, and even chromosomal malformations.

Simple persistent right umbilical vein without abnormalities in other parts is often a benign variation with a good prognosis. Once combined with other deformities, the prognosis often depends on the degree of deformity. Therefore, if a persistent right umbilical vein is found on ultrasound, the ductus venosus should be carefully examined to track the direction of the umbilical vein and ductus venosus to understand whether they are connected to the inferior vena cava. Other parts should also be carefully checked. Those with deformities need to have their chromosomes checked, and if the karyotype is abnormal, the pregnancy should be terminated.