What is the appropriate dosing of Enoxaparin (Low Molecular Weight Heparin) in pregnancy following a cerebrovascular accident (stroke)?

From the Guidelines

Lovenox (enoxaparin) dosing for pregnant women after stroke typically involves therapeutic anticoagulation with 1 mg/kg twice daily subcutaneously, adjusted for weight throughout pregnancy, as recommended by the most recent guidelines 1. This dosing may be monitored using anti-Factor Xa levels, with target ranges of 0.6-1.0 IU/mL for twice-daily dosing, measured 4 hours after injection. Treatment should begin as soon as possible after stroke diagnosis and continue throughout pregnancy and for at least 6 weeks postpartum, as pregnancy and the postpartum period represent times of increased thrombotic risk 1. Dose adjustments may be necessary as pregnancy progresses due to weight gain and physiological changes affecting drug metabolism. Prior to delivery, Lovenox should be discontinued 24 hours before planned induction or cesarean section to reduce bleeding risk, with potential bridging to unfractionated heparin if necessary. Some key points to consider in the management of these patients include:

• Lovenox is preferred over warfarin during pregnancy because it doesn't cross the placenta, avoiding the teratogenic effects associated with warfarin 1.
• Regular monitoring by both neurology and high-risk obstetrics specialists is essential to balance stroke prevention with safe pregnancy management.
• The use of fondaparinux or parenteral direct thrombin inhibitors should be reserved for women with heparin-induced thrombocytopenia (HIT) 1.
• Oral direct thrombin inhibitors and factor Xa inhibitors should also be avoided in pregnancy owing to the lack of safety data 1.

From the Research

Lovenox Dosing in Pregnancy After Stroke

• The safety and efficacy of Lovenox (enoxaparin sodium) in pregnant women have been evaluated in several studies 2, 3.
• A study published in 2002 found that Lovenox therapy appears to be safe and efficacious for pregnant women who are candidates for either prophylactic or therapeutic heparin 2.
• However, the use of enoxaparin and other low-molecular-weight heparins for therapeutic anticoagulation is not recommended for pregnant women with prosthetic heart valves 2.
• In terms of dosing, a study published in 2008 compared the effects of two dose regimens of enoxaparin in the management of deep vein thrombosis (DVT) in pregnancy 3.
• The study found that a single daily dose of 1.5 mg/kg enoxaparin is as effective as twice-daily administration of 1 mg/kg enoxaparin in preventing DVT in pregnant women 3.
• Another study published in 2007 evaluated the efficacy and safety of enoxaparin versus unfractionated heparin for the prevention of venous thromboembolism after acute ischemic stroke 4.
• The study found that enoxaparin reduced the risk of venous thromboembolism by 43% compared with unfractionated heparin, and that the occurrence of any bleeding was similar between the two groups 4.
• A study published in 2002 compared the efficacy, safety, and overall risk-benefit profile of enoxaparin and unfractionated heparin prophylaxis of venous thromboembolic complications in patients with acute ischemic stroke 5.
• The study found that enoxaparin administered subcutaneously once daily was as safe and effective as subcutaneous unfractionated heparin given thrice daily in the prevention of thromboembolic events in patients with lower limb paralysis caused by acute ischemic stroke 5.

Key Findings

• Enoxaparin is safe and effective for preventing DVT in pregnant women 2, 3.
• A single daily dose of 1.5 mg/kg enoxaparin is as effective as twice-daily administration of 1 mg/kg enoxaparin in preventing DVT in pregnant women 3.
• Enoxaparin reduces the risk of venous thromboembolism after acute ischemic stroke compared with unfractionated heparin 4.
• Enoxaparin is as safe and effective as unfractionated heparin in preventing thromboembolic events in patients with acute ischemic stroke 5.