Fetal umbilical-portal-systemic venous shunt diagnosed by prenatal ultrasonography and its association with chromosomal abnormalities

Abstract

Background: Fetuses with umbilical-portal-systemic venous shunt (UPSVS) have poor prognosis, and standard prenatal ultrasound planes do not contain the umbilical-portal-systemic venous system. Moreover, UPSVS-related research is limited, and the rate of chromosomal abnormalities remains unknown. It is necessary to further clarify the ultrasound characteristics and prognosis of these fetuses and develop effective diagnostic models. Accordingly, the objective of this study was to examine the ultrasound image characteristics of fetuses with different types of UPSVS using two-dimensional ultrasound combined with spatiotemporal correlation imaging technology (STIC) and analyzed the chromosomal abnormality rate and pregnancy outcomes.

Methods: A retrospective analysis was performed on fetuses with UPSVS as diagnosed via prenatal ultrasound at Gansu Provincial Maternity and Child Care Hospital from January 2020 to September 2024. Chromosome or gene testing results of UPSVS fetuses, ultrasound characteristics, and the prognosis of fetuses with different types of UPSVS were evaluated. Moreover, a search for literature published from 2000 to 2024 on fetal UPSVS and chromosomal abnormalities was conducted.

Results: A total of 53 fetuses were included in the study. The mean gestational age diagnosed by prenatal ultrasound was 22.2±5.2 weeks. Of the fetuses, 35 fetuses underwent amniocentesis, among whom 25.7% (9/35) had chromosomal or genetic abnormalities (6 type I, 1 type II, and 2 type IIIA). There were 20 cases of terminated pregnancy (9 cases had chromosomal or genetic abnormalities, and 11 cases had severe structural abnormalities), and 33 live births, resulting in 11 cases (34.4%, 11/32; one case was lost to follow-up, and the outcome after birth remained unknown) with poor prognoses. In addition, studies related to fetal UPSVS and their chromosomal or genetic abnormalities published from 2000 to 2024 were analyzed to determine the implications (or indications) of prenatal invasive diagnostic techniques, we found that although most UPAVS fetuses have a good prognosis, the abnormality rate of amniocentesis is about 23.2% (types I and II are more common) when accompanied by other structural abnormalities.

Conclusions: The combination of two-dimensional ultrasound and STIC provides reliable evidence for the diagnosis of UPSVS. Types of UPSVS and chromosomal (or genetic) abnormalities affect the prognosis of UPSVS fetuses.

Keywords: Chromosome abnormality; fetuses; prenatal ultrasound; umbilical-portal-systemic venous shunt (UPSVS).

Figure 1

The normal trajectory of the umbilical portal vein on the transverse section of the fetal abdomen. (A) Portal vein and its branches. (B) Hepatic veins and their branches. DAo, descending aorta; DV, duct venosus; IVC, inferior vena cava; LHV, left hepatic vein; LPV, left branch of the portal vein; LPVi, left inferior branch of the portal vein; LPVm, left middle branch of the portal vein; LPVs, left superior branch of the portal vein; MHV, middle hepatic vein; RAPV, right anterior branch of the portal vein; RHV, right hepatic vein; RPPV, right posterior branch of the portal vein; RPV, right branch of the portal vein; ST, stomach; SP, spine; UV, umbilical vein.

Figure 2

Ultrasound imaging of the middle sagittal plane in type I UPSVS. (A) Two-dimensional CDFI in the median sagittal plane. The white arrow indicates the abnormal shunt. (B) STIC showing the absence of the DV and IHPVS, with the arrow marking the abnormal shunt site (originating from the UV and terminating at IVC). CDFI, color doppler flow imaging; DV, ductus venosus; H, heart; IHPVS, intrahepatic portal vein system; IVC, inferior vena cava; STIC, spatio-temporal correlation imaging technology; UA, umbilical artery; UPSVS, umbilical-portal-systemic venous shunt; UV, umbilical vein.

Figure 3

Ultrasound imaging of the middle sagittal plane in type II UPSVS. (A) CDFI indicating an abnormal diastolic velocity. The white arrow indicates the abnormal shunt. (B) STIC showing the movement of the DV. The arrow indicates the anomalous shunt originating from the DV, with the site of erroneous junction being the IVC. CDFI, color doppler flow imaging; DV, ductus venosus; H, heart; IVC, inferior vena cava; STIC, spatio-temporal correlation imaging technology; UA, umbilical artery; UPSVS, umbilical-portal-systemic venous shunt; UV, umbilical vein.

Figure 4

Ultrasound of the abdominal transverse section in type IIIA UPSVS. (A) MHV widening and an abnormal LPV-MHV connection. The white arrow indicates the abnormal shunt. (B) STIC provides superior visualization of the IHPVS. The white arrow indicates the abnormal shunt between the LPVi and MHV. DV, ductus venosus; IHPVS, intrahepatic portal vein system; LHV, left hepatic vein; LPV, left branch of the portal vein; LPVi, left inferior branch of the portal vein; LPVm, left middle branch of the portal vein; LPVs, left superior branch of the portal vein; MHV, middle hepatic vein; RHV, right hepatic vein; STIC, spatio-temporal correlation imaging technology; UPSVS, umbilical-portal-systemic venous shunt; UV, umbilical vein.

Figure 5

Fetal ultrasound of type IIIB UPSVS. (A) Presence of the IHPVS, absence of the ductus venosus, and widening of the PV before dropping directly into the IVC. The white arrows indicate the abnormal shunt. (B) The STIC shows abnormal shunt between PV and IVC, the white arrows indicate the position of the abnormal shunt. DAo, descending aorta; H, heart; HV, hepatic vein; IHPVS, intrahepatic portal vein system; IVC, inferior vena cava; PV, portal vein; ST, stomach; STIC, spatio-temporal correlation imaging technology; UPSVS, umbilical-portal-systemic venous shunt; UV, umbilical vein.

Figure 6

Prenatal ultrasonography features of UPSVS fetus with abnormal findings on genetic tests. UPSVS, umbilical-portal-systemic venous shunt.

Figure 7

The diagnostic procedure for fetal UPSVS. “Positive” refers to the positive result of amniocentesis; “Negative” refers to the positive result of amniocentesis. CDFI, color doppler flow imaging; DV, ductus venosus; IUGR, intrauterine growth restriction; PV, portal vein; STIC, spatio-temporal correlation imaging technology; UPSVS, umbilical-portal-systemic venous shunt; UV, umbilical vein.