Right umbilical vein is an anatomical variation of the right umbilical vein that does not degenerate in time during embryonic development, also called permanent or persistent right umbilical vein, and is not a malformation. In the fourth week of embryonic development, there are two branches of the umbilical vein, under normal circumstances, as the embryo develops, the right branch gradually degenerates and forms the umbilical ligament. The left umbilical vein concentrates on draining the venous blood from the placenta back to the fetus, part of which enters the liver, and part of which returns to the inferior vena cava and the right atrium; in the case of variation, the left umbilical vein degenerates, and the right umbilical vein serves as a draining agent. Therefore, there is no need to worry too much when the right umbilical vein is detected. No special treatment is needed, and the pregnancy can be continued, but it is necessary to have regular checkups.