Umbilical artery occlusion and fetoplacental thromboembolism

To our knowledge, fetoplacental thromboembolism has been described only in autopsy specimens. We report the antepartum diagnosis of an umbilical artery occlusion and neonatal diagnosis of an aortic thrombus and placental emboli.

A gravida at 31 weeks' gestation was referred for evaluation of decreased fetal movement and an enlarged fetal bladder. A two-vessel umbilical cord with a collapsed, echogenic third vessel was noted, whereas views of a normal three-vessel cord were available from an examination 5 weeks earlier. A positive oxytocin contraction test prompted delivery. Neonatal color flow Doppler imaging demonstrated an aortic thrombus below the renal arteries and above the bifurcation. Gross and microscopic study of the placenta demonstrated necrosis of the collapsed umbilical artery and numerous placental emboli. The aortic thrombus resolved gradually, and the infant went home on the 39th day of life.

Umbilical artery occlusion can be diagnosed ultrasonographically and may be a sign of fetoplacental thromboembolism. Assessment of fetal oxygenation status by biophysical profile or contraction stress test may be helpful in the evaluation of umbilical artery occlusion.