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June 1964

Prothrombin Levels During the First Year of Life: Observations Followed by the Synthetic Substrate (TAMe) Assay of Normal Full-Term Infants

Author Affiliations

Helen I. Glueck, MD, The General Hospital, Department of Medicine, Cincinnati, Ohio 45229.; With the technical assistance of Marjory Wyler.; From the departments of medicine, pediatrics, and The Medical Computing Center, University of Cincinnati, College of Medicine, and the Cincinnati General Hospital.

Am J Dis Child. 1964;107(6):612-617. doi:10.1001/archpedi.1964.02080060614010

The determination of the prothrombin time, particularly the prothrombin content of plasma, is a useful but often neglected liver function test in the adult.1-4 It occurred to us that similar studies might be of value in infancy during the period of life when most liver function tests are of equivocal value.5-7 Since preliminary studies were encouraging, it became important to determine values for prothrombin and the prothrombin complex in the normal full-term infant. These values are the subject of this report.

Materials and Methods  A total of 28 normal full-term infants were followed during the first 12 to 18 months of life. The group included 22 Negro (12 male, ten female) and six white (two male, four female) infants. Each child was regularly examined by one of us (J. S.) in a well-baby clinic. The infants' weights were recorded on each visit. All initial determinations, with two exceptions,