Table 3.19-12. Prevention of VTE in high-risk pregnant women

Clinical setting

Recommended prevention

During pregnancy

Postpartum

History of 1 VTE episode associated with a transient risk factor (except pregnancy and estrogen use)

Careful monitoringa

LMWHb or VKAc

History of 1 VTE episode associated with pregnancy or estrogen use

LMWHd/UFHd

LMWHb or VKAc

History of 1 idiopathic VTE episode (in a patient without thrombophilia and currently not receiving long-term anticoagulant treatment)

LMWHd/UFHd or careful monitoringa

LMWHb or VKAc

History of 1 VTE episode in a patient with low-risk thrombophiliae (currently not receiving long-term anticoagulant treatment)

LMWHd/UFHd or careful monitoringa

LMWHb or VKAc

History of 1 VTE episode in a patient with high-risk thrombophiliaf (currently not receiving long-term anticoagulant treatment)

LMWHg/UFHg

LMWHb or VKAc or LMWH/UFHh

Negative history of VTE in a patient with low-risk thrombophilia

Careful monitoringa

Careful monitoringa or anticoagulant treatment if positive family history of VTE (LMWHb or VKAc)i

Negative history of VTE in a patient with high-risk thrombophiliag

LMWHd/UFHd

LMWHb or VKAc

History of ≥2 VTE episodes in a patient receiving long-term anticoagulant treatment

LMWHj/UFHj

Continuation of long-term treatment used before pregnancy

History of ≥2 VTE episodes (currently not receiving long-term anticoagulant treatment)

LMWHg/UFHg

LMWHb or VKAc or LMWH/UFHh

a Plus prompt diagnostic workup in patients with suspected DVT/PE.

b At a prophylactic dose (see Table 3.19-10) for 4-6 weeks. Do not reduce the dose of LMWH used during pregnancy.

c For 4-6 weeks, INR 2.0-3.0 (initially together with LMWH/UFH until the INR is ≥2.0 for 2 consecutive days).

d At a prophylactic dose.

e Heterozygotes for factor V Leiden mutation, heterozygotes for the prothrombin G20210A gene mutation, deficiency of protein C or protein S.

f Antithrombin deficiency, double heterozygotes for the prothrombin G20210A gene and factor V Leiden, homozygotes for factor V Leiden or homozygotes for the prothrombin G20210A gene.

g Adjusted or prophylactic dose.

h Adjusted dose for 6 weeks.

i If additional risk factors are present (a first-degree relative with an episode of VTE before 50 years of age or other major risk factors for thrombosis, eg, obesity, prolonged immobilization).

j Adjusted dose.

Note: In patients with a history of DVT, use adequately fitted graduated compression stockings during pregnancy, labor, and postpartum.

DVT, deep vein thrombosis; INR, international normalized ratio; LMWH, low-molecular-weight heparin; PE, pulmonary embolism; UFH, unfractionated heparin; VKA, vitamin K antagonist; VTE, venous thromboembolism.