Aetiology, Diagnosis and Treatment of Hydrops Foetalis

Hydrops foetalis is defined as a state of excessive fluid accumulation in the extravascular compartment of the foetus, leading to widespread soft tissue oedema and/or accumulation of fluid in the foetal body cavities. The prognosis of hydrops foetalis is highly dependent on the underlying pathology and early diagnosis is essential to identify treatable cases. The classification of immune and non-immune hydrops foetalis describes the difference between Rhesus haemolytic disease of the newborn and other aetiologies leading to hydrops foetalis. With improved diagnosis and treatment of Rhesus iso-immunisation, non-immune factors have become more frequent. Distinction between anaemic and non-anaemic hydrops foetalis provides a far more useful differentiation between aetiologies. This approach is used to discuss differential diagnosis, work-up and therapeutic options in hydrops foetalis. A structured multidisciplinary work-up will facilitate early diagnosis and assist in making treatment decisions.