VTE in pregnancy
There is a 5- to 10-fold increased risk for VTE during
pregnancy. The risk is increased 100-fold in women with previous
In women with heterozygosity for FV Leiden or PGV, and no
previous thrombotic history, the absolute risk for
pregnancy-associated VTE is low. Women with AT deficiency, PC
deficiency, PS deficiency, homozygosity for FV Leiden, homozygosity
for PGV, or compound heterozygosity are at higher risk.
Women should be clinically assessed for risk of
pregnancy-associated VTE. Testing for heritable thrombophilia is
not generally required. Women with a previous unprovoked VTE should
be tested for the presence of antiphospholipid antibodies.
In women with a VTE during pregnancy a screen for heritable
thrombophilia (FV Leiden, PGV, AT deficiency, PC deficiency, PS
deficiency) should be carried out 6 to 8 weeks after
discontinuation of antithrombotic therapy. Screening for
antiphospholipid syndrome should also be performed.
It may be clinically informative to test asymptomatic women with
a family history of VTE if a thrombosis in a first-degree relative
was unprovoked, or provoked by pregnancy, COCP use, or a minor risk
factor, particularly if this is associated with a known
Women with a family history of VTE and either AT deficiency or
where a specific thrombophilia has not been detected should be
tested for antithrombin deficiency.