A comparison of pregnancy-specific risk scoring systems for venous thromboembolic pharmacoprophylaxis in hospitalized maternity patients

Objective Venous thromboembolism (VTE) remains a leading cause of maternal mortality. The American College of Obstetricians and Gynecologists (ACOG) and the Royal College of Obstetricians & Gynecologists (RCOG) have proposed pregnancy-specific risk scoring guidelines for antepartum (AP) and postpartum (PP) thromboprophylaxis. We compared the impact of scoring thresholds and their potential preventative effect. Study design We conducted a retrospective cohort study of hospitalized maternity patients over a 4-month period. Patients were assigned an AP and PP risk score using each guideline. Hospitalization-associated VTE was accessed over a 6-year period. Comparison was by Fischer's exact and Chi Square tests. Results 638 women were included. Of AP patients, 20% met pharmacoprophylaxis criteria for baseline characteristics and 100% for length of stay using RCOG, and 12% met phrarmacoprophylaxis criteria using ACOG (p < .001). For PP patients, 53% met criteria for RCOG compared to 24% using ACOG (p < .001). If pharmacoprophylaxis were performed at a threshold 1 point above recommendation, 7% of AP patients and 11% of PP women would meet ACOG criteria. This increased ACOG threshold captured all cases of VTE following hospitalization. Conclusion In our population, using ACOG prophylaxis guidelines at an increased threshold would have potentially prevented all hospitalization related VTE without excessive anti-coagulation.