What sample is required?
The determination is made from a venous blood sample.
Is some kind of prior preparation necessary?
A minimum of 10 days must have elapsed since the thrombotic episode and 15 days since the last intake of anticoagulant medication before the test is performed.
Why do the analysis?
To study the cause of recurrent clotting episodes; to diagnose antithrombin deficiencies.
When to do the analysis?
When clots form inexplicably; when a newborn has a severe bleeding disorder; sometimes when a close relative has an inherited deficiency of protein C or protein S.