[Pre- and postnatal diagnosis and treatment of hydrops fetalis--an interdisciplinary problem].

Hydrops fetalis (HF) is diagnosed prenatally in one out of 600 pregnancies, thirty percent of these fetuses will die in utero. Post partum, one out of approximately 25,000 newborn infants is affected. With the introduction of Rhesus immunoprophylaxis only fifty percent of the cases with HF are caused by Rhesus hemolytic disease. There is a large variety of non-immunological reasons such as cardiac defects (hypoplastic left healt syndrome, atrio-ventricular canal), arrhythmias, cytomegalovirus- or parvovirus infection (9% HF), twin-to-twin transfusion syndrome (15-30% HF) or chromosomal abnormalities (28-45% HF). However, in one third of the non immunological cases of HF the etiology remains unclear. Early diagnosis by ultrasound scan faces both the obstetrician and the neonatologist with the problem of differential diagnosis as well as therapeutic options, respectively. Various diagnostic procedures such as fetal echocardiography, karyotyping, molecular genetic techniques and sophisticated serological testings will help to classify the etiology and to determine the pre- and postnatal management. Nevertheless, neonatal mortality still varies between 50 and 95%.