VTE Prophylaxis for Cesarean Section
This patient requires mechanical prophylaxis with sequential compression devices (compression socks) starting preoperatively and continuing until fully ambulatory, with consideration for adding pharmacologic prophylaxis (enoxaparin) based on her risk factor profile. The answer is A. Enoxaparin and compression socks.
Risk Assessment
This 45-year-old woman has multiple VTE risk factors that must be considered:
- Advanced maternal age (45 years) - typically considered a minor risk factor 1
- Obesity (BMI 31) - Class I obesity (BMI 30-34.9), which represents a minor risk factor 1
- Cesarean delivery - inherently increases VTE risk compared to vaginal delivery 1
According to the American College of Chest Physicians (ACCP) risk stratification model, the presence of at least two minor risk factors suggests a VTE risk above 3%, warranting pharmacologic thromboprophylaxis 1.
Recommended Prophylaxis Strategy
Mechanical Prophylaxis (Universal)
All women undergoing cesarean delivery should receive sequential compression devices starting before surgery and continuing until fully ambulatory (GRADE 1C recommendation) 1. This is endorsed by both the Society for Maternal-Fetal Medicine (SMFM) and the American College of Obstetricians and Gynecologists (ACOG) 1.
Pharmacologic Prophylaxis (Risk-Based)
For women at increased risk due to one major or at least two minor risk factors, the ACCP suggests pharmacologic thromboprophylaxis with prophylactic low-molecular-weight heparin (LMWH) while in hospital following delivery (Grade 2B) 1.
Low-molecular-weight heparin (enoxaparin) is the preferred thromboprophylactic agent in pregnancy and the postpartum period (GRADE 1C) 1.
Specific Dosing Considerations
- Standard prophylactic dose: Enoxaparin 40 mg subcutaneously once daily 1
- For Class I obesity (BMI 30-34.9): Standard prophylactic dosing is typically appropriate 2
- For Class III obesity (BMI ≥40): Intermediate doses of enoxaparin should be considered (GRADE 2C) 1
Since this patient has BMI 31 (Class I obesity), standard prophylactic dosing would be appropriate if pharmacologic prophylaxis is initiated 2.
Duration of Prophylaxis
- Mechanical prophylaxis: Continue until the patient is fully ambulatory 1
- Pharmacologic prophylaxis: If risk factors persist postpartum, extended prophylaxis up to 6 weeks after delivery should be considered (Grade 2C) 1
Why Other Options Are Inadequate
Option B (vitamins only) is incorrect because prenatal vitamins provide no VTE prophylaxis, and this patient has identifiable risk factors requiring intervention 1.
Option C (early ambulation alone) is insufficient. While early mobilization is recommended for women without additional risk factors undergoing cesarean section (Grade 1B) 1, this patient has at least two minor risk factors (age 45 and BMI 31) that warrant more aggressive prophylaxis 1.
Option D (aspirin) is not recommended for VTE prophylaxis in the obstetric population. Aspirin has no established role in preventing postoperative VTE after cesarean delivery 1.
Clinical Implementation
The combined approach of mechanical plus pharmacologic prophylaxis is most appropriate for this patient given her risk profile:
- Start sequential compression devices preoperatively 1
- Initiate enoxaparin 40 mg subcutaneously once daily postoperatively 1
- Continue compression devices until fully ambulatory 1
- Consider extending enoxaparin prophylaxis if risk factors persist postpartum 1
Important Caveats
Timing considerations: If neuraxial anesthesia is planned, enoxaparin should be held appropriately (typically at least 12 hours before epidural/spinal placement for prophylactic doses) to minimize bleeding risk 1.
Institutional protocols: The SMFM recommends that each institution develop a patient safety bundle with a standardized protocol for VTE prophylaxis among women undergoing cesarean delivery (Best Practice) 1.