RESUMO
OBJECTIVE: The aim of the study was to better describe incidence, risk factors, and the natural evolution of neonatal portal vein thrombosis (PVT). STUDY DESIGN: One hundred and twenty-three premature newborns or with birth weight <1.5 kg were prospectively included in a single center during a one-year period. Three systematic abdominal ultrasound examinations at day 3, day 10, and day 45 (and 1 year in case of persistent PVT) were performed. Clinical and biological data were recorded. RESULTS: Seventy neonates (57%) had three normal US examinations. Fifty-three neonates (43%) had a clinical and biological asymptomatic left PVT. No right or extrahepatic portal venous thrombosis was observed. Umbilical vascular catheter (UVC) was removed in case of PVT. No anticoagulation therapy was required. No risk factor was significantly associated with PVT. At 1 year of follow-up, five infants had persistent isolated left PVT (4%). CONCLUSION: A spontaneous favorable evolution of left PVT occurred in more than of 95%.