Single umbilical artery is a very common phenomenon, usually does not affect the blood supply of the fetus, non-invasive low-risk is mainly to rule out the risk of fetal Down syndrome, the fetus may be born healthy, but can not be ruled out the existence of other malformations. Single umbilical artery is prone to be combined with malformations of other organs such as neural tube malformations or cardiac malformations. Therefore, during the pregnancy screening test, attention must be paid to the detection of related malformations, and if the single umbilical artery is not combined with other malformations, the fetus is usually healthy after birth. The low risk of non-invasive testing is mainly because the risk of the fetus developing Down syndrome is relatively low, the pregnancy can continue, and the accuracy of non-invasive testing is relatively high. If the single umbilical artery should pay attention to the detector test, after the non-invasive low risk, you can have a normal pregnancy and regular obstetric examination. Comprehensive examination can not only determine the health of the fetus or not, but also can learn about the health of the pregnant woman herself. Pregnant women during pregnancy should pay attention to do a good job of prenatal checkups, and actively listen to the advice of professional doctors to do a good job of comprehensive care and health care, can effectively ensure the safety of the birth.