30th June 2023

Thrombophilia

Pregnancy itself increases the risk of venous thromboembolism (VTE). The presence of hereditary or acquired thrombophilia increases this risk further. Protein C, S or antithrombin deficiency, as well as factor V Leiden and prothrombin gene mutations, are found in the general population and all lead to an increased risk of thrombosis in pregnancy or the first six weeks postpartum. Factor V Leiden (FVL) is the most common heterozygous mutation in the general UK population and so taking a family history is important in considering VTE risk in pregnancy.

Pregnancy alters levels of anticoagulant proteins and as such no testing can be done; genetic mutations, antithrombin and antiphospholipid antibodies can be screened for if this will change management.

Antiphospholipid syndrome (APLS)

Antiphospholipid syndrome is the best-known acquired thrombophilia syndrome and has specific clinical and biochemical diagnostic criteria. Pregnancy where either obstetric history or antiphospholipid antibodies are present count as a risk factor when assessing the need for LMWH in the antenatal and postpartum period.