UMBILICAL VEIN THROMBOSIS

UMBILICAL ARTERY THROMBOSIS

UMBILICAL VEIN THROMBOSIS

• Rare.
• Usually secondary to other diseases that initiate thrombus formation:
• Stricture.
• Torsion.
• Cord hematoma.
• Varix.
• Absence of Wharton's jelly.
• Placental abruption or infection.
• Enlarged bladder has been shown to impede circulation in the lower extremities of the neonate, however it has never been shown to cause aortic thrombus, umbilical arterial occlusion or placental embolization in utero.
• Poorly controlled diabetic mothers are at risk for arterial or venous thrombus.
• Primary umbilical vein thrombus in which no eliciting factor has been reported (1).
• The literature contains only about 20 cases reports of neonatal survival when umbilical vein thrombosis has been diagnosed (2).

UMBILICAL ARTERY THROMBOSIS

• Often accompanies umbilical vein thrombosis (see above causes).
• Only a few cases of selective thrombus formation in the umbilical artery without venous thrombosis have been reported (3,4-5).
• Three cases of survival after umbilical arterial occlusion have been described (2,5). In one case (5) it is suggested that the occlusion was embolic (from an aortic thrombosis). The placental circulation was maintained by Hyrtl's anastomosis at the cord insertion.
• Emboli are usually present in the distal placental vessels (5). These emboli produce vasodilatation of the chorionic surface arteries as well as focal vascular occlusion, which may further decreases placental perfusion (5).
• Has been reported associated with a tight nuchal cord and dural sinus ectasia (6).

Echogenic thrombus in one of the umbilical arteries. The fetus also had hydrometrocolpos.

REFERENCES

1. Eggens JH, Bruinse HW. An unusual case of fetal distress. Am J Obstet Gynecol 1984;148:219.
2. Heifetz SA. Thrombosis of the umbilical cord: Analysis of 52 cases and literature review. Pediatr Pathol 1988;8:37-54.
3. Nayak SK. Thrombosis of the umbilical cord vessels. Aust N Z J Obstet Gynecol 1967;7:148.
4. Devlieger H, Moerman P, Lauweryns J et.al. Thrombosis of the right umbilical artery, presumably related to the shortness of the umbilical cord. An unusual case of fetal distress. Eur J Obstet Gynecol Reprod Biol 1983;16:123.
5. Cook V, Weeks J, Brown J et.al. Umbilical artery occlusion and fetoplacental thromboembolism. Obstetrics and Gynecology 1995;85(5):870-872.
6. Katz ME, Bass WT, White LE. Dural sinus ectasia after prolonged nuchal cord encirclement. J Ultrasound Med 1992;11:289-292.