Antibody neutralizing material of factor VII during the first weeks of life.

In a study on 66 newborns and infants, factor VII activity and factor VII related antigen were investigated on 110 occasions. A normal range was calculated by testing plasma from 12 healthy male volunteers at various dilutions. Most of the values in the newborns and infants fell within this range but 18.2% of the factor VII proteins showed a significantly different specific activity.