Haemostatic failure in babies with rhesus isoimmunization

Abstract

Platelet counts, fibrinogen levels, thrombotest, thromboplastin generation screening test, thrombin ratio, and titre of circulating fibrin degradation products, were measured in 30 infants with Rh isoimmunization, of whom 5 had a bleeding tendency clinically, and 8 had laboratory evidence of disturbed haemostasis.

At necropsy intravascular fibrin deposits were found in the tissues of 3 out of 4 babies who died with haemorrhage.

An additional retrospective survey indicated that haemorrhage had been a major factor in causing death in 10 out of 18 newborn babies who died with rhesus isoimmunization in the period 1967-69.

Sites of haemorrhage at necropsy were mainly intracranial (subarachnoid and intracerebral) and intrapulmonary, with microscopical evidence of intravascular fibrin deposits in 5 cases.

It is concluded that disseminated intravascular coagulation is a major cause of haemostatic failure in babies with rhesus isoimmunization, but that disturbed hepatic synthesis of coagulation factors may also play a part.

Babies at risk from haemostatic failure are those with cord Hb below 7 g/100 ml. It is suggested that a platelet count should be performed as an initial investigation on all such infants.