Chylothorax in a twin pregnancy of 34 weeks--sonographically diagnosed

In a twin pregnancy of 34 gestational weeks sonographic follow-up revealed a rapidly spreading hydrothorax in one twin and slight ascites in the other. Analysis of aspirated fluid by intrauterine needle puncture suggested a chylothorax. Pathogenesis of chylothorax is discussed. Differential diagnosis of hydrothorax is presented. Intrauterine puncture is the only method of achieving prenatal diagnosis and therapy.