Pulmonary arteriovenous fistula ruptured to pleural cavity in pregnancy.

Congenital pulmonary arteriovenous fistula is frequently associated with hereditary haemorrhagic telangiectasia (Rendu-Osler-Weber disease). With the increased blood flow in pregnancy such fistulas enlarge, occasionally giving rise to haemothorax, which generally has a poor prognosis. A familial case is presented in which massive haemothorax required emergency thoracotomy in the 27th week of pregnancy.