Hemostasis Laboratory Diagnostics in Newborns.

The hemostatic system in the newborn is a complex entity, characterized by dynamism in its development; therefore, the correct measurement of its potential is challenging. In this narrative review, we analyzed the current knowledge of the "developmental hemostasis" of the newborn; we also studied the performance of routine coagulation tests in its evaluation, with considerations about the establishment of neonatal age-specific normal ranges and about the role of preanalytical variables, in particular, hematocrit (which could represent an important cause of error); we also focused on the increasing importance of viscoelastic coagulation tests, which are becoming increasingly widespread (especially in some settings such as intensive care unit) and are able to quickly provide information about the hemostatic function of the newborn, even if they lack adequate standardization in the neonatal period.