Objectives: To describe the fetal sonographic characteristics, in-utero natural history and postnatal outcome of choriovitelline placenta, in which the fetal umbilical vein is replaced by the extra-embryonic vitelline circulation. Methods: This was a retrospective study of pregnancies examined during the period 2010–2014. Fetuses which presented with sonographic criteria of a downward caudal course of an enlarged vein from the umbilical annulus to the hepatic hilum were followed prospectively. Two-dimensional and three-dimensional color Doppler with high-definition flow were used in order to investigate the extra- and intrahepatic venous system. Ultrasound images and volumes were stored digitally, clinical data were obtained from patients' medical files and telephone interviews were conducted regarding the course of the pregnancy, perinatal data and developmental milestones. Results: Four cases were identified during the study period. The mean ± SD gestational age at diagnosis was 19.5 ± 4.3 (range, 13–23) weeks. The characteristic downward course of the persistent vitelline vein was associated with aneurysmal dilatation and anomalous anatomical configuration of the intrahepatic venous system. One case ended with antepartum death at 28 weeks. The mean gestational age at delivery was 34.6 (±5.0) weeks and the birth weight corresponded to the 57.2nd (± 16.8 SD) centile. In two cases, a thrombotic mass was detected in the portal venous system after birth. One necessitated antithrombotic treatment for 6 months; in the other case, spontaneous resolution occurred 7 days after birth. In the three surviving infants, the persistent extrahepatic vitelline vein regressed gradually within 6 months after birth. Neurodevelopment was normal at follow-up aged 1 year and 7 months, 3 years and 6 months and 5 years and 5 months. Conclusion: The main clinical importance of choriovitelline placentation derives from the possible formation of thrombus in the portal venous system.