Defibrination syndrome with defective thrombinfibrinogen reaction reversible by protamine

A patient with the obstetric defibrination syndrome successfully treated with human fibrinogen is described. The blood not only contained low levels of fibrinogen capable of clotting but also contained an inhibitor of the thrombin-fibrinogen reaction. This was neutralized in vitro with protamine but it was not heparin. Neither abnormality was detected by a latex agglutination test for plasma fibrinogen. The use of this test does not therefore exclude the diagnosis of the defibrination syndrome.