title: Prothrombin levels in newborn infants by the carinactivase-1 method.
abstract: A recently developed method to quantitate prothrombin in plasma uses the carinactivase-1 (CA-1) method. The present study was designed to establish the reference value by the CA-1 method in the neonatal period and to explore the effect of gestational age, birth weight, concurrent diseases, and vitamin K administration on the prothrombin levels. We enrolled 78 consecutive neonates. The gestational ages ranged from 28 to 41 weeks, and the birth weight ranged from 850 to 3750 g. Twenty-nine infants had concurrent diseases, and the others (n = 49) were healthy. A 300 microL blood sample was drawn into a plastic syringe containing 60 U freeze-dried buffered heparin. Prothrombin levels did not differ between appropriate-for-date (AFD) and light-for-date (LFD) babies (p = 0.090) or between groups with and without concurrent diseases (p = 0.210). In healthy AFD babies, prothrombin levels correlated with gestational age (r = 0.465, p = 0.003) and birth weight (r = 0.458, p = 0.003). In healthy low-birth-weight infants (n = 14) and those with concurrent diseases (n = 17), the changes after vitamin K administration were not significant. The CA-1 method is of clinical use in monitoring coagulation during the early neonatal period.
authors.affiliation: Department of Pediatrics, School of Medicine, University of Occupational and Environmental Health-Japan, 1-1 Iseigaoka, Yahatanishi-ku, Kitakyushu 807-8555, Japan.
authors.forename: Shinji
authors.initials: S
authors.lastname: Fukushima
authors.forename: Toshirou
authors.initials: T
authors.lastname: Tanaka
authors.forename: Tetsuji
authors.initials: T
authors.lastname: Sato
authors.forename: Yoshitsugu
authors.initials: Y
authors.lastname: Shirakawa
authors.forename: Kohtaro
authors.initials: K
authors.lastname: Asayama
authors.forename: Akira
authors.initials: A
authors.lastname: Shirahata
mesh_terms: D001724:Birth Weight; D001774:Blood Chemical Analysis / Q000379:methods / Q000592:standards; D001780:Blood Coagulation Tests; D016022:Case-Control Studies; D005865:Gestational Age; D006801:Humans; D007230:Infant, Low Birth Weight / Q000097:blood; D007231:Infant, Newborn / Q000097:blood*; D007232:Infant, Newborn, Diseases / Q000097:blood; D008666:Metalloendopeptidases; D011516:Prothrombin / Q000032:analysis*; D012016:Reference Values
chemical_list: D011516:Prothrombin; D008666:Metalloendopeptidases; C098667:carinactivase