MFM Consult: Single umbilical artery: What you need to know

October 1, 2010

A 23-year-old woman is found to have a fetus with a single umbilical artery at the time of initial ultrasound, which was performed at 18 weeks' gestation. Read about other abnormalities that are associated with a single umbilical artery.

Q: A 23-year-old woman (gravida 1,para 0) is found to have a fetus with a single umbilical artery at the time of initial ultrasound, which was performed at 18 weeks' gestation. What other abnormalities are associated with a single umbilical artery?

An isolated SUA with no other structural or chromosomal abnormalities should be distinguished from an SUA that is present with other abnormalities. The rate of associated fetal structural anomalies when an SUA is detected has been reported to range from 13% to 56%.3 The most common associated anomalies have been noted to occur in the renal, cardiovascular, gastrointestinal, and central nervous systems. Genetic syndromes that may feature an SUA include VATER complex (a group of congenital anomalies consisting of vertebral defects, imperforate anus, tracheoesophageal fistula, and radial and renal dysplasia), Meckel-Gruber, and Zellweger. Teratogenic exposures such as maternal hyperglycemia and phenytoin have also been associated with SUA.

If there are no other evident fetal abnormalities, how should this patient be further evaluated? Is additional testing indicated if additional fetal abnormalities are identified?