Two abnormal different patterns of umbilical venous drainage are seen in cases of ADV . The UV may connect directly to the portal vein without giving rise to the DV (intrahepatic shunt); UV may bypass the liver and may connect to the subdiaphragmatic IVC, renal veins or iliac veins; UV may directly connect to the right atrium intrahepatic IVC, coronary sinus or even left atrium (extrahepatic shunts). Absent ductus venosus with intrahepatic drainage has rarely been reported in literature [6–8]. Absent ductus venosus is an uncommon anomaly with reported incidence varying from 1 in 2,532 in a very large study of 65,840 pregnancies at 11–14 weeks , to 6/1,000  in high risk cases. Absent ductus venosus is associated with morphological abnormalities in approximately 65 %cases and cytogenetic abnormalities in 17 % cases [4, 6].
The study by Staboulidou et al.  also showed a strong association of ADV with aneuploidies and a marked increase in the incidence of abnormal outcomes when ADV was associated with increased Nuchal translucency measurements (NTL) above 95th centile for crown rump length (CRL) (66.7 % incidence of aneuploidy, mostly Turner syndrome) as compared to cases when ADV was an isolated finding and associated with normal NTL measurements (81.8 % normal healthy live births).
Systemic abnormalities associated with ADV include [4, 6, 10] cardiac (atrial and ventricular septal defects, tricuspid atresia, double outlet right ventricle pulmonary atresia and transposition of great arteries) gastrointestinal (duodenal atresia, tracheoesophageal fistula) genitourinary system (hydronephrosis, ectopic kidney) and musculoskeletal abnormalities. One of the most critical associations of ADV is the complete or partial agenesis of the portal venous system  usually in cases where the UV bypasses the liver resulting in severe postnatal complications like pulmonary edema, focal nodular hypoplasia and hepatic tumors. The presence of associated chromosomal and structural abnormalities determines the prognosis in both intrahepatic and extrahepatic drainage of the UV. In cases of extrahepatic drainage of the UV, the prognosis, additionally, depends on the extent of development of the portal venous system and its resultant complications, the site of drainage of the UV (shunt site) , and the shunt diameter  in relation to the umbilical vein diameter. Closer the UV drains to the right heart bypassing the liver, presumably, more the preload and more the likelihood of intrauterine heart failure. The farther the UV drains from the right heart and narrower the shunt diameter, lesser the preload, lower the likelihood of intrauterine heart failure. Cases with relatively smaller shunt diameters, compared to the UV diameter show better development of the portal venous system and hence better outcome [6, 11, 12]. In general, extrahepatic umbilical venous drainage results in worst fetal outcomes compared to intrahepatic drainage of the UV [6, 8, 11, 12].
Gembruch et al.  reported two cases of intrahepatic drainage of the umbilical vein in 1998 with ADV in second and third trimesters without the development of hydrops or compromising fetal hemodynamics. They suggested that absence of the DV may be compatible with normal fetal development without relevant disturbance of circulation and oxygenation. Berg et al.  also concluded that ADV without liver bypass seems to have better prognosis in the absence of other malformations. In cases of intrahepatic shunts, as in the present case, the presence of a normal portal venous system and an intervening high resistance bed between the UV and right heart (hepatic venous sinusoids and hepatic veins) probably prevents hepatic complications and increased preload .
The commonest cause of nonvisualization of DV is technical, resulting from unfriendly fetal positions, maternal body habitus and surgical scars. Repeated examinations are a must to exclude technical cause of DV non visualization. Modern ultrasound equipment allow excellent multiplanar visualization of the umbilical–portal venous anatomy in 2D, Doppler and 3D power Doppler modes for enhanced diagnostic confidence . In cases of confirmed ADV the normalcy of portal venous system, site of UV drainage (intrahepatic or extrahepatic) and diameter of the abnormal shunt in relation to the caliber of the UV should be ascertained. Karyotype, a detailed morphological and cardiac assessment in expert hands is also important. The patient should be counseled regarding the complications and the risk of intrauterine fetal death, hydrops, cardiac failure and expected postnatal course. Delivery should preferably be conducted in a tertiary center with facilities to manage complications including surgical or device closure of abnormal shunts . Recurrence risk of ADV is not known but probably depends on the associated chromosomal and structural abnormalities.