[Prophylaxis of thrombosis in a pregnant woman with congenital antithrombin III deficiency: changes in hemostatic molecular markers before the onset of thrombosis].

A pregnant woman with congenital antithrombin III (AT III) deficiency was given AT III concentrate and warfarin at the first and after 36th week of gestation periods and at the other gestation period, respectively. The patient developed thrombosis in the left leg, but fibrinopeptide A (FPA) and thrombin-AT III complex (TAT) had already shown high values one week before, suggesting the possibility of their being forecast markers of thrombosis. The administration of AT III concentrate caused an improvement in thrombosis. Therefore, in case of high FPA and TAT values as determined one or two times a week, the administration of AT III concentrate was thought necessary. In case of warfarin, however, non-administration during the 6th-9th weeks of gestation for the purpose of avoiding teratogenicity and frequent blood coagulation tests taking heed of overdosage for the purpose of avoiding fetal central nervous system abnormalities were suggested necessary. Delivery was uneventful, both mother and child being doing very well; umbilical blood AT III activity was 18%. It is generally difficult for us to form the diagnosis as AT III deficiency only from AT III activity at neonatal stage, but in the present study, we analyzed the restriction fragment length polymorphism of the AT III gene using umbilical blood, and succeeded in diagnosing the neonatal child as AT III deficiency.