VTE Prophylaxis Recommendation
This patient requires both enoxaparin 40 mg subcutaneously once daily and sequential compression devices (Answer A). 1, 2
Risk Stratification
This 45-year-old woman has at least two minor risk factors that elevate her VTE risk above 3%, warranting pharmacologic thromboprophylaxis:
- Advanced maternal age (45 years) - classified as a minor risk factor 1, 3
- Obesity (BMI 31, Class I obesity) - represents a minor risk factor 1, 2
- Cesarean delivery - inherently increases VTE risk compared to vaginal delivery 1, 2
The American College of Chest Physicians (ACCP) guidelines specify that the presence of at least two minor risk factors indicates VTE risk exceeding 3%, which triggers the need for pharmacologic prophylaxis. 1
Recommended Prophylaxis Protocol
Mechanical Prophylaxis
- Apply sequential compression devices before surgery and continue until the patient is fully ambulatory (GRADE 1C recommendation) 4, 1, 2
- This applies to all women undergoing cesarean delivery regardless of risk factors 4, 1
Pharmacologic Prophylaxis
- Enoxaparin 40 mg subcutaneously once daily is the preferred agent (GRADE 1C recommendation) 1, 2, 3
- Low-molecular-weight heparin (LMWH) is first-line over unfractionated heparin due to easier administration and lower adverse event rates 5, 6
- Initiate enoxaparin 6-12 hours after cesarean delivery if no increased hemorrhage risk 7
Duration of Prophylaxis
- Mechanical prophylaxis: Continue until fully ambulatory 1, 2
- Pharmacologic prophylaxis: At least 10 days postpartum for intermediate-risk patients 2, 3
- Consider extending to 6 weeks postpartum if additional risk factors persist 1, 3
Why Other Options Are Inadequate
Option B (vitamins only) is inappropriate because pregnancy vitamins provide no VTE protection, and this patient's risk profile clearly requires active prophylaxis. 1, 2
Option C (early ambulation alone) would be acceptable only after vaginal delivery with obesity as the sole risk factor, but is insufficient for cesarean delivery with multiple risk factors. 2
Option D (aspirin) has no role in VTE prophylaxis during pregnancy or postpartum; antiplatelet agents do not prevent venous thrombosis. 1
Important Clinical Considerations
- BMI 31 uses standard dosing (40 mg once daily); intermediate dosing (40 mg every 12 hours) is reserved for Class III obesity (BMI ≥40) 1, 3
- Renal function: Enoxaparin is contraindicated if creatinine clearance <30 mL/min; switch to unfractionated heparin in this scenario 4, 3
- Timing matters: Hold LMWH at labor onset or at least 12 hours before elective cesarean section to allow for neuraxial anesthesia 7
- The number needed to treat to prevent one VTE in high-risk postpartum women ranges from 640-4000, but the intervention is strongly recommended given the potentially fatal consequences 3