**4.3. Umbilical artery aneurysm**

Umbilical artery aneurysm is an extremely rare vascular anomaly usually associated with high risk of fetal aneuploidy, IUGR, and fetal demise. Fetal demise is a result of compression of the dilated artery on the umbilical vein, thrombus formation, or due to associated fetal anomaly like trisomy 18 [43]. This condition is a vascular anomaly which appears as an anechoic cyst close to cord insertion with a hyperechogenic rim in which color flow and spectral Doppler examinations show nonpulsatile and turbulent blood flow within the artery [44].

It is important to consider karyotype analysis given the high incidence of aneuploidy associated with umbilical artery aneurysm.

Tumors of the Umbilical Cord
