Maternal antenatal administration of vitamin K1 results in increasing the activities of vitamin K-dependent coagulation factors in umbilical blood and in decreasing the incidence rate of periventricular-intraventricular hemorrhage in premature infants

Aims: Infants less than 35 weeks' gestation age are susceptible to periventricular-intraventricular hemorrhage (PIVH). This may be partially attributable to low concentrations of vitamin K-dependent coagulation factors. The purposes of this study were: (1) to determine the umbilical blood activity levels of vitamin K-dependent coagulation factors II, VII, IX and X; (2) to investigate the change in activities of these factors in premature infants' umbilical blood after prenatal administration of vitamin K 1 to the mothers; and (3) to study the prophylactic effects on PIVH after maternal antenatal supplemental vitamin K-1. Methods: Pregnant women in preterm labor at less than 35 weeks of gestation were randomly selected to receive antenatal vitamin K-1 10 mg per day injection intramuscularly or intravenously for 2-7 days (vitamin K-1 group, n=40), or no such treatment (control group, n=50). At the same period, cord blood samples were collected from thirty full-term neonates to compare the factor levels with those of premature infants. Intracranial ultrasound was performed by the same sonographer to determine the presence and severity of PIVH. Results: The activities of vitamin K-dependent coagulation factors in umbilical blood in the control group were: factor II 25.64 +/- 9.49%, factor VII 59.00 +/- 17.66%, factor IX 24.67 +/- 8.88%, and factor X 30.16 +/- 5.02%. In fullterm infants, the respective values were: factor II 36.70 +/- 4.88%, factor VII 64.54 +/- 10.62%, factor IX 30.18 +/- 5.69%, and factor X 34.32 +/- 12.63%. In vitamin K 1 group these factors were: factor II 36.35 +/- 6.88%, factor VII 69.59 +/- 16.55%, factor IX 25.71 +/- 10.88%, and factor X 39.26 +/- 8.02%. The data suggest the absence of vitamin K-dependent coagulation factors in preterm infants, and antenatal supplement of vitamin K-1 may increase the cord blood activity of factor II, VII and factor X (P < 0.001). In addition, the overall rates of PIVH in the vitamin K-1 group and in controls were 32.4 and 52.0%, respectively (P=0.036), and the frequency of severe PIVH was 5.0 and 20.0%, respectively (P=0.038). Conclusions: Administration of vitamin K-1 to pregnant women at less than 35 weeks' gestation age may result in improved coagulation and may reduce the incidence as well as the severity degree of PIVH.