[Chyloperitoneum in newborn infants].

The authors describe a newborn, in which a diagnosis of ascites was made before birth by ultrasound. Ascites without other signs of hydrops may be caused by meconium-peritonitis, perforation of the bile ducts, disorders of the portal or systemic circulation, flow disturbances in the lymphatic vessels, urinary obstruction or a ruptured ovarian cyst. In this case there was a chylous ascites in a child with Down's syndrome. Diagnosis, pathogenesis and treatment are discussed. With conservative treatment the child was free of symptoms at the age of 6 months.