Single umbilical artery is the most common umbilical cord anomaly. The disadvantages include high incidence of fetal malformations, fetal growth restriction, chromosomal abnormalities, etc. The advantages are that the fetus may be able to grow normally. 1. Disadvantages: single umbilical artery placenta is more likely than normal umbilical cord vascularized placenta to have high level placental vascular perfusion abnormality, which can easily lead to fetal growth restriction; single umbilical artery can cause cardiovascular and tracheo-esophageal abnormalities by disrupting hemodynamics, which can lead to fetal malformations; single umbilical artery has a high incidence of chromosomal abnormality in the fetus and chromosomal examination is recommended. 2. Benefits: If the umbilical artery compensatory dilatation, the normal single umbilical artery fetus can also grow normally, which is the most favorable side of the many disadvantages. Therefore, when the fetus has a single umbilical artery, you should actively consult a specialist, cooperate with the completion of the relevant examinations, and build up good confidence. If the fetus is found to have a single umbilical artery, it is recommended that malformation screening and chromosome testing be performed. For more information about single umbilical artery, please consult your specialist in detail and seek timely medical attention so as to avoid any delay in your condition.