Thrombosis and thrombophilia - Whole blood and components

Essential information

Definition/s

Thrombophilia is a condition in which there is an increased tendency for blood clots to form. It is often inherited and may be discovered through family studies. Not all individuals with a thrombophilic condition will suffer from blood clots.

Antithrombotic therapy refers to drugs used to prevent and treat thrombosis. This includes:

• anticoagulant drugs such as heparin, warfarin, direct oral anticoagulants (DOACs) (e.g. apixaban)
• antiplatelet drugs such as aspirin, clopidogrel, dipyridamole

Obligatory

For acquired thrombophilia, see: is there a specific entry for the underlying cause?

Must not donate if:

1. Due to atherosclerosis (e.g. coronary thrombosis)
2. Two or more episodes of thrombosis requiring treatment
3. Less than 7 days after completing anticoagulant therapy
4. Has thrombophilia and has had 1 or more episodes of thrombosis
5. Has thrombophilia associated with a history of recurrent superficial thrombophlebitis
6. Has thrombophilia and requires prophylactic antithrombotic treatment for flights, for pregnancy, or for surgery or other procedures, due to their thrombophilia
7. History of vaccine-induced thrombotic thrombocytopenia (VITT), thrombotic thrombocytopenic purpura (TTP) or heparin induced thrombocytopenia (HIT)

Discretionary

1. If a first episode of thrombosis, such as deep vein thrombosis (DVT), retinal vein thrombosis or pulmonary embolism (PE):
   1. If no underlying cause that excludes the donor has been identified, and
   2. The donor is not known to have thrombophilia, and
   3. The donor is well and anticoagulant therapy (if used) has been stopped for at least 7 days, accept.
      
      
2. If the potential donor has thrombophilia and,
   1. The donor is not on (prescribed or non-prescribed) antithrombotic therapy, and
   2. The donor has never had an episode of thrombosis, and
   3. The donor has not been treated with antithrombotic therapy for recurrent pregnancy loss, and
   4. The donor has never been treated with plasma-derived clotting factor concentrates, and
   5. The donor has never required, or been advised they require, prophylactic antithrombotic treatment for flights, pregnancy, or surgery or other procedures because of their thrombophilia, and
   6. If relevant, the underlying cause of an acquired thrombophilia (see Additional information below) does not exclude the donor, accept.
      
      
3. If the potential donor has a history of axillary vein thrombosis, refer to a Designated Clinical Support Officer.
   
   
4. If the donor has a history of superficial thrombophlebitis (superficial vein thrombosis) see Superficial thrombophlebitis.

Supporting information

See if relevant

• Anticoagulant therapy
• Autoimmune disease
• Cardiovascular disease
• Drugs and platelet donation (drug index)
• Malignancy
• Nonsteroidal anti-inflammatory drugs
• Superficial thrombophlebitis

Additional information

Thrombophilia is a broad medical term which describes a multifactorial condition where the blood has an increased tendency to clot. Individuals with thrombophilia can present with arterial or venous thrombosis. The causes of thrombophilia include inherited and acquired disorders, and a combination of causes may be present.

Inherited causes of thrombophilia may be discovered through family testing. These include:

• Antithrombin, Protein C and Protein S deficiency
• Factor V Leiden and prothrombin gene mutations

Acquired causes of thrombophilia may present later in life and can be associated with:

• Malignancy including myeloproliferative neoplasms
• Antiphospholipid syndrome and other autoimmune connective tissue disorders. These may be associated with a lupus anticoagulant and/or anti-cardiolipin antibodies on laboratory testing.

Retinal vein thrombosis (also known as retinal vein occlusion) is a form of retinal vascular disease and can affect central or branch retinal veins. The condition is uncommon under the age of 60 but becomes more frequent in later life. The condition may be associated with risk factors including hypertension, hyperlipidaemia, diabetes mellitus, atherosclerosis and smoking.

VITT, TTP and HIT are rare disorders characterised by arterial or venous thrombosis in combination with a low platelet count (due to platelet consumption). Donors who recover from these disorders are unlikely to be eligible to donate due to the therapy they received (e.g. the primary treatment for TTP is plasma exchange with FFP) or an underlying condition (e.g. the indication for heparin therapy that triggered HIT). VITT was recognised as a complication of some SARS-CoV-2 (COVID-19) vaccinations.

Axillary vein thrombosis can be precipitated by excessive use of the arm (e.g. sports or working above head level) but other precipitants include venous compression in thoracic outlet syndrome, diabetes, smoking, malignancy and venous canulation. The donor may be eligible to donate if the underlying cause has been identified and corrected, but this should be balanced with the remote risk of local complications from a subsequent donation.

Superficial thrombophlebitis, also known as superficial vein thrombosis, is a common condition, usually (but not exclusively) affecting the lower limbs. It is characterised by inflammation in a superficial vein associated with clot formation. This is different to, and less serious than, a deep vein thrombosis (DVT). If the superficial clot extends to where the superficial and deep veins join, a DVT can develop. Superficial thrombophlebitis normally settles within 2 to 6 weeks. Some individuals may be treated with anticoagulants to reduce the risk of extension. Recurrent superficial thrombophlebitis is sometimes associated with a diagnosis of thrombophilia.

Donors with a thrombophilia may be advised that they require prophylactic antithrombotic treatment at times when they could be at increased risk of developing a thrombosis, such as during long-haul flights, pregnancy, or when undergoing or recovering from a surgical or other procedure. The risks of thrombosis are cumulative; blood donation and local adverse effects (e.g. haematoma) could pose additional risks in an individual already at increased risk, and therefore it is advised that these donors should not donate.

Regulatory information

Part of this entry is a requirement of the Blood Safety and Quality Regulations 2005.

Reason for change:

Addition of definition of antithrombotic therapy. Clarification regarding eligibility in relation to prescribed or non-prescribed antithrombotic therapy. Addition of guidance for donors with thrombophilia requiring prophylactic antithrombotic treatment.

Version:

Antithrombotic treatments

Version details:

WB-DSG Edition 203 Release 81 (11 August 2026)