Evolving Fetal Biometry in Fetal Intrahepatic Portosystemic Shunt With Late-Onset Preeclampsia and Focal Umbilical Cord Hypercoiling: A Case Report.

Fetal intrahepatic portosystemic shunt may complicate fetal growth assessment, particularly when maternal and umbilical cord abnormalities coexist. We report a pregnancy first evaluated at our center at 26 + 3 weeks for suspected severe early-onset fetal growth restriction, with estimated fetal weight below the 1st percentile and abdominal circumference below the 3rd percentile. Prenatal ultrasound and fetal magnetic resonance imaging findings were consistent with fetal intrahepatic portosystemic shunt. Subsequent serial assessments showed improved fetal biometry. Routine umbilical artery and ductus venosus assessments were not clearly abnormal, whereas middle cerebral artery pulsatility index decreased in late gestation. A focal hypercoiled cord segment showed a higher umbilical artery systolic-to-diastolic ratio than routine sampling. Delivery at 35 + 2 weeks was indicated by severe preeclampsia and a positive oxytocin challenge test. The neonate was appropriate for gestational age, with postnatal ultrasound confirmation of persistent shunting and mild hyperammonemia.