An in-vitro study of acidosis, platelet function, and perinatal cerebral intraventricular haemorrhage.

Platelet aggregation in response to adenosine diphosphate was studied in umbilical-vein blood from 24 term infants. The pH of platelet-rich plasma was experimentally reduced by adding increasing concentrations of lactic acid or by exposure to carbon dioxide. Aggregation was significantly impaired by acidosis and there was a significant positive correlation between falling pH and impaired platelet aggregation in both experiments. Impaired platelet aggregation secondary to acidosis may be a factor in perinatal intracerebral haemorrhage.