VTE Prophylaxis for Cesarean Section in a 45-Year-Old Woman with BMI 31
This patient requires combined mechanical and pharmacologic prophylaxis with sequential compression devices plus enoxaparin 40 mg subcutaneously once daily, making option A (Enoxaparin and compression socks) the correct answer. 1
Risk Stratification
This patient has two minor risk factors that together warrant pharmacologic thromboprophylaxis:
- Advanced maternal age (45 years) - classified as a minor risk factor for VTE 1
- Class I obesity (BMI 31) - represents a minor risk factor for VTE 1
- Cesarean delivery - inherently increases VTE risk compared to vaginal delivery 1
The American College of Chest Physicians (ACCP) guidelines specify that the presence of at least two minor risk factors indicates a VTE risk above 3%, which warrants pharmacologic thromboprophylaxis. 1
Recommended Prophylaxis Strategy
Mechanical Prophylaxis (Universal for All Cesarean Deliveries)
- Sequential compression devices must be used starting before surgery and continuing until the patient is fully ambulatory (GRADE 1C recommendation) 2, 1
- This applies to ALL women undergoing cesarean delivery, regardless of additional risk factors 2
Pharmacologic Prophylaxis (Required for This Patient)
Low-molecular-weight heparin (enoxaparin) is the preferred thromboprophylactic agent in pregnancy and the postpartum period (GRADE 1C). 2, 1
- Standard prophylactic dose: Enoxaparin 40 mg subcutaneously once daily 1
- Should be initiated postoperatively 1
- The American Society of Hematology (ASH) recommends standard-dose LMWH prophylaxis over intermediate-dose during the postpartum period 2
Important Dosing Consideration for This Patient
While this patient has Class I obesity (BMI 31), intermediate-dose enoxaparin is only recommended for Class III obesity (BMI ≥40). 1 Therefore, standard dosing of 40 mg once daily is appropriate for this patient.
Duration of Prophylaxis
- Mechanical prophylaxis: Continue until fully ambulatory 2, 1
- Pharmacologic prophylaxis: Consider extension up to 6 weeks after delivery if risk factors persist postpartum (Grade 2C) 1
Why Other Options Are Incorrect
Option B (Continue vitamins, no prophylaxis)
This is dangerous and contradicts all major guidelines. The ASH guidelines explicitly state that while evidence for prophylaxis in women with only one clinical risk factor may be limited, this patient has multiple risk factors (age, obesity, cesarean delivery). 2 The ACCP clearly recommends pharmacologic prophylaxis when at least two minor risk factors are present. 1
Option C (Early ambulation alone)
While early ambulation is beneficial, mechanical prophylaxis alone is insufficient for patients with multiple risk factors. 1 The Society for Maternal-Fetal Medicine (SMFM) and ACOG recommend combined mechanical plus pharmacologic prophylaxis for patients with a high-risk profile. 1
Option D (Antiplatelets with aspirin)
Aspirin has no role in VTE prophylaxis in this context. The evidence-based approach requires LMWH, not antiplatelet therapy. 2, 1
Clinical Implementation
- Initiate sequential compression devices preoperatively 1
- Start enoxaparin 40 mg subcutaneously once daily postoperatively 1
- Continue compression devices until fully ambulatory 1
- Consider extending enoxaparin for up to 6 weeks postpartum given persistent risk factors 1
Common Pitfalls to Avoid
- Do not rely on mechanical prophylaxis alone in patients with multiple risk factors - pharmacologic prophylaxis is necessary 1
- Do not confuse BMI thresholds - intermediate dosing is for BMI ≥40, not BMI 31 1
- Do not assume vitamins provide any VTE protection - they have no anticoagulant properties 2
- The SMFM recommends that each institution develop a standardized protocol for VTE prophylaxis among women undergoing cesarean delivery to ensure consistent application of these principles. 1