Intra‐Abdominal Umbilical Vein Varix With Postnatal Portal Vein Thrombosis: A Case Report

Intra-abdominal umbilical vein varix (UVV) is an uncommon vascular anomaly of the fetal umbilical vein that may be accompanied by thrombosis and adverse pregnancy outcomes in some cases (1). Portal vein thrombosis (PVT) in newborns is also uncommon and is often secondary to coagulation dysfunction, infection, or umbilical vein catheterization (2). We report a 23-year-old primiparous woman whose fetus was diagnosed with UVV at 24 + 2 weeks of gestation, with turbulent flow on ultrasound. Serial follow-up ultrasounds at 28 + 3, 31 + 0, and 36 + 0 weeks of gestation showed progressive enlargement of the varix and persistent abnormal flow characteristics. Following cesarean delivery of a male infant, abdominal ultrasound on postnatal day 3 revealed portal vein and ductus venosus thrombosis. Laboratory findings suggested a transient hypercoagulable state, with concurrent infection and metabolic acidosis. Despite no obvious short-term interval resolution of the thrombotic lesions after anticoagulation and supportive treatment, the infant improved clinically and was discharged on postnatal day 9. This case highlights the importance of serial prenatal ultrasound surveillance and early postnatal follow-up, with particular attention to the risk of portal vein thrombosis when umbilical vein abnormalities are detected prenatally.