What is the Royal College of Obstetricians and Gynaecologists (RCOG) recommended thromboprophylaxis for pregnant women at high risk of venous thromboembolism (VTE)?

RCOG Thromboprophylaxis for Pregnant Women at High Risk of VTE

According to the Royal College of Obstetricians and Gynaecologists (RCOG) guidelines, pregnant women at high risk of venous thromboembolism (VTE) should receive both mechanical and pharmacologic thromboprophylaxis with low-molecular-weight heparin (LMWH) for at least 6 weeks postpartum. 1

Risk Assessment and Classification

The RCOG risk assessment model stratifies pregnant women into different risk categories:

• High Risk: Women who require at least 6 weeks of postpartum thromboprophylaxis with LMWH
• Intermediate Risk: Women who require 10 days of postpartum thromboprophylaxis with LMWH
• Low Risk: Women who require only early mobilization without pharmacologic prophylaxis

High Risk Factors Include:

• Previous VTE (personal history of deep venous thrombosis or pulmonary embolism)
• High-risk thrombophilia (antithrombin deficiency, homozygous Factor V Leiden, homozygous prothrombin G20210A mutation, or combined heterozygous Factor V Leiden and prothrombin mutations)
• Low-risk thrombophilia with additional risk factors
• Multiple risk factors that persist into the postpartum period

Recommended Prophylaxis Protocol

For pregnant women at high risk of VTE, RCOG recommends:

1. Antepartum Period:

   • Prophylactic LMWH throughout pregnancy
   • Regular clinical assessment for signs of VTE

2. Intrapartum Management:

   • Discontinue LMWH at the onset of labor or prior to planned delivery
   • For planned cesarean section, discontinue LMWH at least 12 hours before the procedure 2

3. Postpartum Period:

   • Resume LMWH 4-6 hours after vaginal delivery or 6-12 hours after cesarean section (if no increased bleeding risk) 2
   • Continue LMWH for at least 6 weeks postpartum 1, 3
   • Add mechanical prophylaxis (sequential compression devices) until fully ambulatory 1

Pharmacologic Agents

• First-line agent: Low-molecular-weight heparin (LMWH) is the preferred thromboprophylactic agent 1, 3

  • Options include:
    • Enoxaparin 40 mg once daily
    • Dalteparin 5000 U once daily 4
    • For women with class III obesity, intermediate doses of enoxaparin are recommended 1

• Alternative: Warfarin (target INR 2.0-3.0) may be initiated postpartum if preferred 3

  • Both LMWH and warfarin are safe for breastfeeding mothers 3

Special Considerations

Women with Previous VTE:

• All women with prior VTE should receive postpartum prophylaxis for 6 weeks 3, 5
• Those with unprovoked, pregnancy/estrogen-related VTE, or multiple VTEs should also receive antepartum prophylaxis 3

Women with Thrombophilia:

• Women with high-risk thrombophilias (antithrombin deficiency, protein C or S deficiency, homozygous Factor V Leiden or prothrombin mutation) require both antepartum and postpartum prophylaxis 3, 5
• Women with low-risk thrombophilias and positive family history should receive postpartum prophylaxis 3

Implementation Considerations

• Institutional protocols should be developed for VTE prophylaxis 1
• Regular monitoring for signs of recurrent VTE and bleeding complications is essential 3
• The postpartum period carries a substantial risk of VTE recurrence (6.5% without prophylaxis vs. 1.8% with prophylaxis) 3

Common Pitfalls to Avoid

1. Inadequate duration: Postpartum thromboprophylaxis should continue for the full 6 weeks in high-risk women, not just during hospitalization
2. Improper dosing: Standard prophylactic doses may be insufficient in women with class III obesity or very high risk of VTE 6
3. Delayed initiation: Postpartum LMWH should be resumed promptly after delivery once hemostasis is achieved
4. Neglecting mechanical prophylaxis: Sequential compression devices should be used in addition to LMWH until the patient is fully ambulatory

By following these RCOG-based recommendations, clinicians can significantly reduce the risk of VTE-related morbidity and mortality in high-risk pregnant women.