What is the recommended management of cortical venous thrombosis in pregnancy?

Management of Cortical Venous Thrombosis in Pregnancy

Initiate therapeutic-dose low-molecular-weight heparin (LMWH) immediately upon diagnosis of cortical venous thrombosis and continue throughout pregnancy and for at least 6 weeks postpartum, with a minimum total treatment duration of 3 months. 1

Immediate Anticoagulation Strategy

Start therapeutic anticoagulation without delay as soon as cortical venous thrombosis is confirmed on imaging—do not wait for additional testing or specialist consultation, as treatment delays directly increase mortality and morbidity. 1

Preferred LMWH Regimen

• Enoxaparin 1 mg/kg subcutaneously twice daily is the preferred regimen for acute cortical venous thrombosis 1
• Alternatively, enoxaparin 1.5 mg/kg subcutaneously once daily is acceptable 2, 1
• LMWH is strongly preferred over unfractionated heparin (UFH) because it provides more predictable therapeutic levels, superior efficacy, lower risk of heparin-induced thrombocytopenia, and reduced osteoporosis risk 2, 1

When to Use Unfractionated Heparin

• Reserve UFH with aPTT monitoring only for patients with severe renal impairment (eGFR <30 mL/min) 1

Critical Medications to Avoid

Never use the following agents during pregnancy:

• Vitamin K antagonists (warfarin) are absolutely contraindicated due to embryopathy risk and potential fetal bleeding 1, 3
• Direct oral anticoagulants (dabigatran, apixaban, edoxaban, rivaroxaban) are contraindicated due to placental transfer and insufficient safety data 1
• Fondaparinux should be avoided as it crosses the placenta and lacks adequate safety evidence in pregnancy 1

Monitoring Requirements

• Routine anti-factor Xa level monitoring is not required unless there are specific concerns such as extreme body weight, uncertain therapeutic effect, or renal impairment 2, 1
• Anti-Xa monitoring should be avoided as a routine practice to guide LMWH dosing 2

ICU Admission Criteria

Admit to the intensive care unit if:

• Any hemodynamic instability is present 1
• Altered mental status occurs 1
• Advanced gestational age with concerns about fetal viability requires continuous fetal monitoring 1

Duration of Anticoagulation

Therapeutic-dose LMWH must continue:

• Throughout the entire pregnancy 1
• For at least 6 weeks postpartum 2, 1
• With a minimum total treatment duration of 3 months from the time of diagnosis 1

This extended duration is necessary because pregnancy-associated hypercoagulability persists for 6-8 weeks after delivery, with the highest risk of thrombotic complications occurring postpartum. 4, 5

Peripartum Management

Timing of LMWH Discontinuation

• Discontinue LMWH 24 hours before scheduled delivery to minimize intrapartum bleeding risk 1, 6
• This planned discontinuation requires coordination with obstetrics for scheduled induction or cesarean delivery 2

Resumption of Anticoagulation

• Resume anticoagulation 8-12 hours after vaginal delivery if bleeding is controlled 1, 6
• Resume anticoagulation 12-24 hours after cesarean section if bleeding is controlled 1

Neuraxial Anesthesia Considerations

• Anesthesia consultation is mandatory for epidural or spinal anesthesia decisions 1
• LMWH must be stopped at least 24 hours prior to epidural or spinal placement 1

Common Pitfalls to Avoid

Critical errors that increase maternal mortality:

• Do not use prophylactic-dose anticoagulation for acute cortical venous thrombosis—therapeutic dosing is mandatory 1
• Do not postpone therapeutic anticoagulation while awaiting additional imaging or specialist consultation 1
• Do not rely on clinical symptoms alone to exclude venous thromboembolism, as failure to investigate symptoms is a consistent finding in maternal death enquiries 7

Breastfeeding Considerations

• LMWH, UFH, and warfarin are all safe options during breastfeeding and do not require cessation of nursing 2
• This allows continuation of therapeutic anticoagulation throughout the postpartum period without interrupting breastfeeding 2

Rationale for Aggressive Treatment

Pregnancy-associated venous thromboembolism, including cortical venous thrombosis, is a leading cause of maternal morbidity and mortality in developed countries. 2 The absolute risk of VTE increases 6-10-fold during pregnancy compared with age-matched non-pregnant women, and many of these deaths are preventable with optimal anticoagulation. 4, 8