[Appearance of coagulation disorders in the non-healthy newborn infant].

Coagulation abnormalities are particularly frequent in neonatal pathology and justify exploration of hemostasis in the newborn. First of all we established a profile of coagulation in the newborn using our own results and data from the literature. Contrasting with a deficit in numerous factors (II - VII - IX - X - XI - and XII), overall coagulation is normal, or even increased. The fibrinolytic system is characterized by a low plasminogen level but the activity of this system is transitorily increased. Then we recall the known syndromes: avitaminosis K, constitutional deficits in the coagulation factors, isolated thrombopenia, disseminated intravascular clotting. However numerous problems persist. Abnormalities in the clotting factors are frequently difficult to interpret. Correlation between the clinical and laboratory pictures does not always exist. We emphasize the necessity for preventive measures.