How should I manage a patient with APS who is planning to become pregnant, considering the risks of thrombosis?

Management of a patient with antiphospholipid syndrome (APS) planning pregnancy should include:

• Pre-pregnancy specialist referral: Refer the woman to a haematologist or specialist with expertise in thrombosis in pregnancy for assessment and formulation of a thromboprophylaxis plan, especially if there is a history of venous thromboembolism (VTE) or abnormal thrombophilia screen.
• Medication review and adjustment: Stop warfarin before conception due to its teratogenicity and switch to low molecular weight heparin (LMWH) or heparin, as appropriate, under specialist guidance.
• Thromboprophylaxis during pregnancy: Initiate LMWH early in pregnancy and continue throughout pregnancy and the puerperium to reduce the risk of thrombosis.
• Aspirin prophylaxis: Advise low-dose aspirin (75–150 mg daily) from 12 weeks’ gestation until birth to reduce the risk of pre-eclampsia and improve pregnancy outcomes, as APS is an autoimmune condition associated with increased pre-eclampsia risk.
• Multidisciplinary care: Collaborate with rheumatologists if there is coexisting autoimmune disease and ensure regular monitoring and adjustment of anticoagulation dosing, including anti-Xa levels if indicated.
• Pre-conception counselling: Provide counselling about the risks of thrombosis, pregnancy complications, and the importance of medication adherence and monitoring.

This approach aims to minimise maternal and fetal risks associated with APS and thrombosis during pregnancy.

References: NICE CKS, NICE CKS, NICE NG89, NICE CKS