Developmental hemostasis: clinical implications from the fetus to the adolescent.

The coagulation system involves a dynamic group of procoagulation and anticoagulation proteins that appear early in fetal life and whose levels change throughout childhood and into the teenage years. This process is called developmental hemostasis. Developmental hemostasis creates unique challenges for clinicians affecting the diagnosis and treatment of coagulation disorders during early childhood. The objective of this review is to assist pediatricians in understanding the coagulation system in fetal life and childhood and to provide guidance for interpreting basic coagulation testing, which will result in an improved ability to diagnose and treat patients with hemostatic and thrombotic disorders.