American Board of Internal Medicine (ABIM) Certification Practice Exam

For anticoagulation management of atrial fibrillation from weeks 13-37 of pregnancy, which method is recommended?

1. Continue warfarin

2. Only use UFH

3. Weight-based LMWH and UFH

4. Discontinue all anticoagulation

The correct answer is: Weight-based LMWH and UFH

For anticoagulation management of atrial fibrillation during weeks 13 to 37 of pregnancy, the recommended approach is to utilize weight-based low molecular weight heparin (LMWH) along with unfractionated heparin (UFH) when necessary. This recommendation is based on the understanding that warfarin, while effective for anticoagulation, poses significant risks to the developing fetus, especially during the first and third trimesters. By the second trimester (weeks 13-27), the risks associated with warfarin decrease compared to the first trimester, but it is still not the preferred choice due to potential teratogenic effects and the risk of fetal bleeding. Using LMWH, which has a more favorable safety profile during pregnancy, allows for adequate anticoagulation while minimizing fetal risks. It provides effective management by preventing venous thromboembolism and is less likely to cause complications than warfarin. Additionally, the use of UFH may be considered in specific scenarios where rapid reversal of anticoagulation is needed, although LMWH typically suffices for routine management. In summary, weight-based LMWH is the preferred anticoagulation method during the second and early part of the third trimester, ensuring safety for both the