However, nonimmunogenic causes were found to be associated with this syndrome: placental chorioangioma, Ebstein's anomaly, viral infections in pregnancy, aneurysmal malformation of the Galen vein, and other fetal malformations .
Other causes associated with the onset of the syndrome in the case studies included multiple pregnancies (10 cases); viral infections such as Coxsackie B, cytomegalovirus, and parvovirus B19 (nine cases); tumors and congenital anomalies such as placental chorioangioma, fetal aortic stenosis, Galen's vein aneurysm, cystic hygroma in the fetal neck, and fetal sacrococcygeal teratoma, among other unknown causes.
Our patient had accompanying right atrial enlargement, tricuspid insufficiency, and chorioangioma. In the light of this case, we planned to review the related literature on ductus venosus agenesis.
After a detailed fetal ultrasound was performed, the patient was found to have right atrial enlargement, cardiomegaly, tricuspid regurgitation, ductus venosus agenesis, hyperdynamic flow in the umbilical vein, and chorioangioma. The 22-week 6-day-old fetus, which was estimated based on the time from the last menstrual period, was found to be 21 weeks 4 days using fetal biometric measurements.
Frequently the etiology of IUGR is unknown; however in several cases it is possible to identify fetal (infection, malformation, and chromosomal aberration ), placental  (chorioangioma
, infarction, circumvallated placenta, confined placental mosaicism, obliterative vasculopathy of the placental bed, etc.), maternal (chronic hypertension , pregestational diabetes, cardiovascular disease , substance abuse, autoimmune conditions, etc.), and external factors that modulate the normal fetal growth, by acting on a genetically predetermined potential growth .
Focal aneurysmal dilatation of subchorionic vessels simulating chorioangioma
. Ultrasound Obstet Gynecol.
The other causes of cystic placentas are partial molar pregnancy, complete mole with coexisting normal foetus, chorioangioma
, subchorionic haematoma, confined placental mosaicism and spontaneous abortion with hydropic changes.
Five cases of chorioangioma
. J Obstet Gynaecol Br Emp.
constitutes the commonest benign tumour of placenta (1).
E/o 2 placental mass lesion--likely to be Chorioangioma