The influence of perinatal risk factors on the incidence of atypical coagulation factor VII during the first days of life.

The correlation between the appearance of functionally-atypical factor VII and perinatal complications was investigated in 66 newborn infants. The presence of an abnormal clotting factor was assumed if the ratio between clotting activity and antigen-related factor VII material exceeded the normal range for adult plasma. The newborns were divided into a risk group of infants threatened by adverse conditions of labour or post-natal adaptation, and a control group of newborns without perinatal complications. The findings were as follows: The incidence of atypical factor VII was significantly higher in the risk group. There was no difference between prenatal and postnatal complications in this respect. Infants born by caesarian section or with cord complications, as well as those with delayed respiratory adaptation, showed a higher incidence of atypical factor VII than the risk group as a whole. Atypical factor VII was not detected until the third day of life, irrespective of the prenatal or postnatal complications. These findings suggest that perinatal risk factors are associated with an alteration of factor VII synthesis.