INTRODUCTION:In the fetus, the Ductus venosus (DV) connects the umbilical vein and the portal veins to the inferior vena cava in order to bypass the high-resistance hepatic vascular network. Via the Eustachian valve, the DV directs umbilical venous blood with the highest oxygen content preferentially towards the myocardium and the brain. An absence (agenesis) or a secondary obliteration of an initially normally developed DV (atresia) is associated with various shunt types and may lead to severe hydrops.
CASE REPORT:A routine check-up of a healthy 34-year-old woman at 27 5/7 wks GA revealed a severe hydrops fetalis with pleural effusions and ascites. After birth at 28 0/7 wks GA, the bilateral pleural effusions needed drainage via thoracic drains. Arterial hypotension was initially treated with volume replacement and dopamine, later on adrenaline and hydrocortisone were added. The initial echocardiography showed normal anatomic structures and normal bi-ventricular function. Despite maximal intensive care treatment, a global respiratory and cardiovascular insufficiency developed. The girl died on fourth day of life. At autopsy, a secondary atresia of the DV was identified, and moreover a pathogenic de novo heterozygous mutation in the KRAS gene was found in the chorion biopsy probe.
DISCUSSION:For all cases of non-haemolytic hydrops fetalis, a prenatal or postnatal sonography with Doppler examination of the venous system and of the heart should be performed. Furthermore, testing for RASopathies should be recommended especially in presence of increased nuchal translucency thickness and polyhydramnios.