Can Lovenox (enoxaparin) be used in pregnant women with Pulmonary Embolism (PE)?

Use of Lovenox (Enoxaparin) in Pregnant Women with Pulmonary Embolism

Low molecular weight heparin (LMWH), specifically Lovenox (enoxaparin), is the recommended treatment for pulmonary embolism (PE) in pregnant women and should be administered throughout the entire pregnancy. 1, 2

Rationale for Using Lovenox in Pregnancy

• Lovenox does not cross the placenta and is not found in breast milk in significant amounts 1
• Appears safe and efficacious for pregnant women requiring either prophylactic or therapeutic anticoagulation 3, 4
• Avoids the risks associated with vitamin K antagonists (warfarin), which can cause:
  • Embryopathy during the first trimester
  • Fetal and neonatal hemorrhage in the third trimester
  • Placental abruption
  • Central nervous system anomalies throughout pregnancy 1

Dosing and Administration

• Weight-adjusted dosing should be used:
  • 200 IU/kg once daily OR
  • 100 IU/kg twice daily 2
• Anti-Xa monitoring may be considered in women with:
  • Extremes of body weight
  • Renal disease
  • Other clinical indications 1, 2
• Routine monitoring is generally not required 2

Management During Labor and Delivery

• Discontinue Lovenox at the onset of regular uterine contractions 2
• For planned delivery, discontinue Lovenox at least 24 hours before 2
• If epidural analgesia is desired:
  • Lovenox must be discontinued at least 24 hours prior to insertion of epidural needle 1, 2
  • Do not insert a spinal or epidural needle within 24 hours of the last therapeutic dose 1
  • Do not administer Lovenox within 4 hours after removal of an epidural catheter 1

Postpartum Management

• Resume Lovenox 12-24 hours after delivery or epidural catheter removal 1, 2
• Continue anticoagulation for at least 6 weeks postpartum with a minimum total treatment duration of 3 months 1, 2
• Transition to vitamin K antagonists may be considered postpartum, as they are safe during breastfeeding 1, 2

Special Considerations

• For high-risk, life-threatening PE during pregnancy:
  • Unfractionated heparin (UFH) is typically used in the acute treatment 1
  • Consider conversion from LMWH to UFH ≥36 hours prior to delivery in high-risk situations 1
  • Thrombolysis or surgical embolectomy should be considered only in critical cases when the patient is likely to die and surgical embolectomy is not immediately available 1, 2

Cautions and Contraindications

• Lovenox and other LMWHs are not recommended for pregnant women with prosthetic heart valves 3, 4
• Direct oral anticoagulants (NOACs) are contraindicated during pregnancy 1

Multidisciplinary Approach

• Close collaboration between obstetrician, anesthesiologist, and attending physician is essential for optimal management 1, 2
• A multidisciplinary pregnancy heart team should be involved in planning ante-, peri-, and post-partum care 1

Efficacy and Safety Data

• Studies have shown Lovenox to be effective in preventing venous thromboembolism during pregnancy 5, 6
• Maternal side effects are uncommon and include:
  • Mild localized allergic reactions (2%)
  • Increased bleeding (2%, dose-dependent) 7
• Heparin-induced thrombocytopenia is very rare and bone resorption is not clinically relevant 7

Lovenox represents the standard of care for pregnant women with PE, offering effective anticoagulation with minimal risks to both mother and fetus when properly administered and monitored.