VTE Prophylaxis for Scheduled Cesarean Delivery in 45-Year-Old Obese Woman
This patient requires combined mechanical and pharmacologic thromboprophylaxis with sequential compression devices plus enoxaparin 40 mg subcutaneously once daily, making option A (Enoxaparin and compression socks) the correct answer. 1, 2
Risk Stratification
This patient has two minor risk factors that together elevate her VTE risk above the 3% threshold requiring pharmacologic prophylaxis:
- Advanced maternal age (45 years): Classified as a minor risk factor by ACCP guidelines 1, 2
- Class I obesity (BMI 31): Represents a minor risk factor for VTE 1, 2
- Scheduled cesarean delivery: Inherently increases VTE risk 4-fold compared to vaginal delivery 3
The American College of Chest Physicians explicitly states that the presence of at least two minor risk factors indicates VTE risk exceeding 3%, warranting pharmacologic thromboprophylaxis 1, 2. The combination of age ≥35 years and obesity creates a cumulative risk profile that mandates intervention beyond early ambulation alone 4.
Recommended Prophylaxis Strategy
Mechanical Prophylaxis (Universal Requirement)
All women undergoing cesarean delivery must receive sequential compression devices starting before surgery and continuing until fully ambulatory, regardless of additional risk factors (GRADE 1C recommendation) 1, 2. This is non-negotiable and applies even to low-risk patients 1.
Pharmacologic Prophylaxis (Required for This Patient)
Enoxaparin 40 mg subcutaneously once daily is the preferred agent for this patient with Class I obesity (BMI 31) 2. The Society for Maternal-Fetal Medicine and ACOG recommend prophylactic low-molecular-weight heparin for women with one major or at least two minor risk factors 1, 2.
Important dosing distinction: Standard prophylactic dosing (40 mg once daily) is appropriate for BMI 31 2. Intermediate-dose enoxaparin (40 mg every 12 hours) is reserved for Class III obesity (BMI ≥40), which does not apply to this patient 2.
Duration of Prophylaxis
- Mechanical prophylaxis: Continue until fully ambulatory 1, 2
- Pharmacologic prophylaxis: Consider extension up to 6 weeks postpartum if risk factors persist (Grade 2C) 1, 2
Why Other Options Are Incorrect
Option B (Continue vitamins, no prophylaxis): This approach ignores established guidelines and would be appropriate only for women with zero risk factors undergoing cesarean delivery 1. The ACCP explicitly recommends no prophylaxis other than early mobilization only when no risk factors are present 1. This patient's age and obesity disqualify her from this low-risk category 2, 4.
Option C (Early ambulation alone): While early mobilization is recommended for all patients, it is insufficient as sole prophylaxis when two or more minor risk factors are present 1. The ACCP guidelines clearly state that early mobilization alone is appropriate only for women without risk factors 1.
Option D (Antiplatelets with aspirin): Aspirin has no role in VTE prophylaxis for cesarean delivery 1. Antiplatelet agents do not prevent venous thromboembolism; low-molecular-weight heparin is the evidence-based pharmacologic agent 2.
Critical Implementation Details
- Timing of enoxaparin initiation: Begin 12 hours after neuraxial block (or 4 hours after epidural catheter removal if using standard prophylactic dosing) 2
- Contraindication screening: Verify creatinine clearance >30 mL/min; if lower, use unfractionated heparin instead 2
- Institutional protocol: SMFM recommends standardized VTE prophylaxis bundles for all cesarean delivery patients (Best Practice) 1, 2
Common Pitfalls to Avoid
Do not underestimate cumulative risk: The combination of advanced maternal age and obesity creates a multiplicative effect that mandates intervention 4. Each factor alone might seem modest, but together they cross the threshold for pharmacologic prophylaxis 1, 2.
Do not delay mechanical prophylaxis: Sequential compression devices must be applied before surgery, not after the patient reaches the postpartum unit 1.
Do not use compression stockings alone: While the question mentions "compression socks," the evidence specifically supports sequential compression devices (pneumatic compression), which are more effective than static elastic stockings 1.