Acarboxy Prothrombin in Cord Plasma from Normal Neonates

Acarboxy prothrombin was detected in the plasma of 48 of 128 umbilical cord plasma samples and in all of 65 patients receiving coumadin. None was found in 20 normal adults. Although the prevalence was the same in blacks, whites, and neonates of mixed origin, levels were significantly higher in blacks. There was a negative correlation between the level of acarboxy prothrombin and the prothrombin index. There was no correlation between maternal age, birth weight, gestational age, obstetrical complications, race, socioeconomic status, albumen, or u-foetoprotein and the incidence of cord plasma acarboxy prothrombin.