A 28 year old pregnancy G1P0 8 weeks gestational age is diagnosed with a leg DVT. What is the risk of VTE in the pregnant population? What should she be treated with and for how long?
The principle behind this case is to recognize that the prevalence of VTE is higher in the pregnant population which is 2/ 1000 deliveries; a 4-5 fold increased risk compared to non-pregnant females. Over 80% of clots are in the venous system with 90% of them in the left leg later in trimester due to compression of the left iliac vessels from the gravid uterus.
Therapy should exclude warfarin at minimum during the 6th to 12 weeks of gestation to avoid the teratogenic effects including nasal hypoplasia and stippled epiphyses. Patients are placed on a LMWH with Factor Xa levels monitored to account for changes in weight and CrCl throughout the pregnancy and must continue on anti-coagulation for a minimum of 6 weeks post-partum.
James, A. Venous thromboembolism in pregnancy. Arterioscler Thromb Vasc Biol. March 1, 2009 vol. 29 no. 3 326-331