Title:
Impact of a risk-based thromboprophylaxis protocol on postpartum bleeding and healthcare resource utilization

Authors:
Michelle Y. Lu^1,2, Victoria C. Jauk^2,3, Elizabeth B. Ausbeck^1,2, Kacie R. Oglesby², Rodrigo D. Muñoz Rogers², Allison J. Lazenby², Margaret R. Page², Dhong-Jin Kim^1,2, Brian Casey^1,2, Jeff M. Szychowski^1,3, Akila Subramaniam^1,2

Institutions:
¹Center for Women’s Reproductive Health, University of Alabama at Birmingham, Birmingham, AL

²Department of Obstetrics and Gynecology, University of Alabama at Birmingham, Birmingham, AL

³Department of Biostatistics, University of Alabama at Birmingham, AL

Background:

• Heparin-based anticoagulation for venous thromboembolism (VTE) prophylaxis in pregnant and postpartum women is not without potential risk.

• We compared measures of postpartum bleeding and resource utilization before and after adoption of a risk-based VTE prophylaxis protocol

Study Design:

• Retrospective cohort study of all deliveries at a single tertiary care center from 2013-2018
• Deliveries were categorized as pre- or post-protocol

• • Pre-protocol deliveries:

• • • Delivered in 2013-2015
    • No standardized VTE prophylaxis

• • Post-protocol deliveries:

• • • Delivered in 2016-2018
    • Algorithm for anticoagulation based on antepartum/postpartum risk factors (Table 1)

• • Of note, a more restrictive institutional transfusion practice was adopted in 2015

• Exclusion criteria:

• • Patients receiving anticoagulation for active VTE or high risk of VTE

• Outcomes:

• • Postpartum bleeding parameters

• • • Delivery estimated blood loss (EBL, ml)
    • Receipt of uterotonics
    • Receipt of packed red blood cells (pRBCs, units)
    • Maximum hemoglobin change (g/dL)

• • Postpartum resource utilization

• • • Number of hemoglobin/hematocrit studies ordered
    • Patients with platelet studies evaluated
    • Number of lower extremity Doppler ultrasounds obtained
    • Pulmonary computed-tomography angiograms (CTA) obtained
    • Maternity triage unit visits
    • Number of patients readmitted
    • Number of patients admitted to intensive-care units (ICU)

• Analysis:

• • Outcomes were compared between pre-protocol and post-protocol cohorts
  • Odds ratios (95% CIs) were calculated with the pre-protocol cohort serving as the referent group

Results:

• Of 24,232 deliveries identified, 11,799 (49%) were pre- and 12,433 (51%) were post-protocol
• Please see Table 2. We found that:

• • Women post-protocol were 15x more likely to receive anticoagulation (16% vs. 1%, p<0.001)
  • Postpartum uterotonic use was similar between groups, but more women were transfused post-protocol despite more restrictive transfusion practices
  • No clinically significant differences were seen in other bleeding parameters
  • There were more platelet studies ordered post-protocol but there were no changes in use of other resources detected
  • Despite increased anticoagulation use, imaging studies for suspected VTEs were not different

Conclusions:
Adoption of a risk-based VTE prophylaxis protocol was associated with increased anticoagulation and blood product transfusion without a decrease in clinical evaluation of suspected VTE. Further studies to quantify if this protocol reduces VTE events or increases wound or bleeding complications are planned.