Routine coagulation tests in newborn and young infants.
BACKGROUND
The diagnostic approach to haemostatic defects in the newborn is challenging and requires appropriate interpretation of coagulation tests according to reference values dependent on the postnatal age.


METHODS
This investigation was designed to study the postnatal development of the human coagulation system in newborn infants and to develop appropriate reference ranges for prothrombin time (PT), activated partial thromboplastin time (APTT) and fibrinogen (FBG) according at the day of birth and for the following postnatal period (days 1, 2, 3, 4, 5, 6, from 7 to 10 and from 11 to 44).


RESULTS
The mean FBG value was already within the adult reference range in newborns at birth, the mean PT value fell within the adult reference range in infants aged 4 days or more, whereas the mean APTT value was still higher than the upper limit of the adult reference range in infants aged between 11 and 20 days. The prevalence of infants with pathological values according to the actual adult reference ranges was limited for FBG (from 24 to 7%), decreased from 92 to 8% in infants aged 0 and 11-20 days for PT, but remained elevated throughout the observational period for APTT (from 94 to 71%).


CONCLUSIONS
The results of the present investigation demonstrate that the actual adult reference ranges for coagulation screening tests, especially PT and APTT, cannot be applied to newborns and young infants.
Lippi
Giuseppe
G
Sezione di Chimica Clinica, Dipartimento di Scienze Morfologico-Biomediche, Ospedale Policlinico G.B. Rossi, Università degli Studi di Verona, Piazzale Scuro, 10, 37134 Verona, Italy. ulippi@tin.it
Salvagno
Gian Luca
GL
Rugolotto
Simone
S
Chiaffoni
Gian Paolo
GP
Padovani
Ezio Maria
EM
Franchini
Massimo
M
Guidi
Gian Cesare
GC
D000328:Adult; D001777:Blood Coagulation / Q000502:physiology; D001780:Blood Coagulation Tests / Q000592:standards*; D005340:Fibrinogen; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D008403:Mass Screening; D010314:Partial Thromboplastin Time; D011517:Prothrombin Time; D012016:Reference Values
D005340:Fibrinogen