- Neonatal portal vein thrombosis (PVT) is an increasingly recognized event. Patients are generally asymptomatic in the neonatal period. The diagnosis is made with Doppler ultrasound. Umbilical catheterization, exchange transfusion and sepsis are risk factors for neonatal PVT. Thrombophilia is possibly a contributing risk factor. Although there are potential serious acute complications such as hepatic necrosis, the outcome is good in the majority of cases, followed up to 8 years of age. Thrombus resolution occurs in 30-70% in days to months. Liver lobe atrophy may occur following PVT, and does not appear to be associated with any impairment of liver function. Non-occlusive thrombosis is more likely to resolve than non-occlusive thrombosis. A subset of patients without resolution is at risk for developing portal hypertension over the next decade of life. There are no current defining features present during the neonatal period to enable identification of neonates at risk for portal hypertension. There is no evidence that anticoagulation therapy improves time to resolution or decreases the likelihood of portal hypertension. Anticoagulation therapy may be considered. A management algorithm is proposed.