Prenatal Ultrasound Diagnosis of Fetal Type IV Intrahepatic Portosystemic Shunt: A Rare Case Report.

Fetal intrahepatic portosystemic shunt (IPSS) is a rare vascular anomaly that poses significant postnatal risks. Paul et al. classified congenital IPSS into four types: (I) a single large tube connecting the right portal vein to the inferior vena cava; (II) a localized peripheral shunt with communications in one hepatic segment; (III) an aneurysmal shunt; (IV) multiple diffuse communications in both lobes. We report a unique case of Type IV IPSS diagnosed at 29 weeks of gestation using prenatal ultrasound and Doppler imaging. The shunt was characterized by tortuous portal vein branches draining into hepatic veins, accompanied by fetal growth restriction and mild tricuspid regurgitation. This case highlights the value of detailed prenatal imaging for accurate diagnosis, classification, and perinatal planning. Early identification and close monitoring of fetal IPSS can optimize neonatal outcomes and guide postnatal interventions.