Abstract
A 28-year-old primigravida with spontaneous conception and no complicating medical
illness presented to the authors for an early morphology scan. Her scan was unremarkable
with normal nuchal translucency for crown rump length, no stigmata for chromosomal
abnormalities and no major detectable structural abnormality. A repeated search for
ductus venosus revealed non visualization of the ductus with intrahepatic drainage
of the umbilical vein. The karyotype was normal. Fetal echocardiogram, anomaly and
serial growth scans were also within normal limits. She developed mild hydramnios
in the late third trimester and delivered a normal healthy female child at 37 weeks.
Postnatal echocardiogram showed a very small muscular ventricular septal defect. Mild
pulmonary stenosis has been diagnosed at the age of 6 months. Ductus venosus is the
key regulator of oxygenated blood in fetal life. Absent ductus venosus is associated
with multiple structural, chromosomal, cardiac abnormalities partial or complete absence
of portal venous system, hydrops and fetal death. In the absence of ductus venosus
the umbilical vein may drain normally into the liver (intrahepatic shunt) or may drain
in an aberrant location into the systemic circulation (e.g., iliac vein, inferior
vena cava, right heart and coronary sinus) creating an extrahepatic shunt. In all
the cases of absent ductus venosus, the prognosis depends on the presence or absence
of associated abnormalities. In cases of extrahepatic aberrant drainage of the umbilical
vein, the prognosis depends upon the presence or absence of portal venous system,
abnormal shunt site and shunt diameter. In general, intrahepatic variant has a much
better prognosis in the absence of other abnormalities.
Keywords
Absent ductus venosus - Intrahepatic shunt - Extrahepatic shunt - Congenital absence
of portal venous system - Aberrant drainage of umbilical vein - Turner syndrome
