[Effects of acid-base balance and Apgar score on fibrinopeptide A and fibrinopeptide B beta 15-42 in umbilical cord blood].

Previous studies on asphyxia neonatorum show that the infant's blood is in a state of hypercoagulability at such a time. In the present study, we determined the amount of fibrinopeptide A (FPA) and fibrinopeptide B beta 15-42 (FPB beta), new sensitive indicators of the coagulation-fibrinolytic system, in the newborn, and examined their relationship to the acid-base balance in umbilical artery blood in elective cesarean section and vaginal delivery, as well as to the Apgar score (Ap. S). In addition, the findings in umbilical cord blood were then compared with those in the blood of normal adults. The results were as follows: In vaginal delivery, infants with Ap. S at 5-7, pH, had significantly lower HCO-3 and BE readings lower while PCO2 was significantly increased, which indicated respiratory and metabolic acidosis. In the vaginal delivery group, FPA was significantly increased in infants with pH under 7.24, PCO2 over 50 mmHg, BE under -8 and Ap. S at 5-7, and as well as in infants in the elective cesarean section group with Ap. S at 5-7. This suggests that the production of thrombin is accelerated if the fetus is asphyxiated. FPB beta was not significantly different among groups. However, FPB beta was significantly higher in various vaginal delivery groups than in the elective cesarean section group (Ap. S greater than or equal to 8), which implies acceleration of the production of plasmin and fibrinolysis in vaginal delivery. FPA and FPB beta were markedly increased in umbilical cord blood as compared with the blood of normal adults. This suggests that blood coagulation and fibrinolysis were accelerated in umbilical cord blood.