What are the indications for referring a patient with suspected APS to a specialist for further evaluation?

Indications for referring a patient with suspected antiphospholipid syndrome (APS) to a specialist include:

• History of venous thromboembolism (VTE), such as deep vein thrombosis or pulmonary embolism, especially if thrombophilia screening is abnormal or if there is recurrent VTE.
• Women with APS or suspected APS who are planning pregnancy or are pregnant, due to increased risks of complications such as pre-eclampsia, placental infarction, intrauterine growth restriction, and fetal death.
• Patients requiring interpretation of thrombophilia test results, as this should be done by clinicians with expertise in thrombosis and thrombophilia.
• Women on warfarin or other oral anticoagulants who are planning pregnancy, as warfarin is teratogenic and specialist advice is needed to manage anticoagulation safely during pregnancy.
• Patients with APS who have underlying rheumatological conditions (e.g., systemic lupus erythematosus), especially if they are on immunosuppressive or disease-modifying drugs, warranting rheumatology referral.

Referral to a haematologist or rheumatologist with expertise in thrombosis and autoimmune conditions is recommended for these patients to ensure appropriate management and counselling.

These indications are based on UK guidelines emphasizing specialist involvement in managing thrombophilia and APS, particularly in the context of pregnancy and recurrent thrombotic events ¹.