Fetal right subclavian artery vagus on ultrasound usually does not require induction of labor, which is the cause of congenital vascular developmental anomalies in the fetus. Fetal right subclavian artery vagus, also known as ectopic right subclavian artery, is a congenital developmental anomaly of the aortic arch. The pathogenesis is related to the genetic inheritance of the fetus. It is best to go to the hospital to check non-invasive DNA, 4D ultrasound and fetal heart ultrasound and other related examinations to clarify whether there are other abnormalities. Generally right subclavian artery vagus does not affect the function after birth and does not cause wheezing after activity. The alignment of the blood vessels is different from normal, and the origins of the blood vessel branches are different from others, which usually does not have a significant impact on the child’s health. If the symptom of fetal vagus right subclavian artery occurs in the clinic, please go to the hospital for examination without delay, so as to avoid adverse consequences.