When someone gets a clot in pregnancy, do you anticoagulate them for the entire time, or do you anticoagulate them for 6 months and then switch to thromboprophylaxis? Also, do you ever ultrasound their legs or lungs to see what the clot is doing in order to choose?

Helen Feltovich, MD, Maternal-Fetal Medicine
Intermountain Healthcare, Provo, UT

At our institution, we fully anticoagulate a patient who gets a clot in pregnancy throughout pregnancy and for at least three months postpartum (PP), usually six months PP. We know from studies of clot incidence that there is still signal related to the increased incidence surrounding pregnancy as far out as three months. We do not image them until we are making a decision to stop anticoagulation and that is usually six months PP. I say "we," but at that time it is our Heme/Coag team who is making the decision. They will also check a d-dimer and assess other risk factors when deciding whether to stop or continue. In Europe, our heme/epi colleagues are concerned about the high rate of recurrence among their patients who receive low dose anticoag for a history of clot, let alone for a clot during that pregnancy. I just have been asked to participate on a steering committee for an international randomized trial of low vs. full dose anticoag for women with a history of clot. My impression is that the risk of recurrent clot is MUCH higher among women who have had a clot during that pregnancy. I am just not comfortable reducing a woman's anticoag to a low dose when she has had a clot during pregnancy, especially when all the risk factors that gave her a clot in the first place are still present. Then, PP, her risk increases another 5- to 20-fold higher than it was during pregnancy.

Andra James, MD, MPH
Founder of the Women's Hemostasis and Thrombosis Clinic
Duke University Medical Center
Associate Professor of Obstetrics & Gynecology
Duke University School of Medicine
Durham, NC