(912) Clinical Reliability of a Hemorrhage Risk Assessment in a Safety-Net Hospital

Objective: Postpartum hemorrhage (PPH) is the leading cause of maternal morbidity and mortality in the U.S. While PPH is defined, consensus is lacking regarding risk stratification tools for antepartum and intrapartum management. We sought to evaluate our CMQCC-based hemorrhage risk assessment (HRA) tool (Figure 1) and assess its reliability in predicting stage III PPH in a safety-net hospital.

Study Design: We performed a retrospective cohort study using all patients with PPH at our tertiary care center from September 2020 to March 2022. The HRA tool was scored on admission, at shift change, and prior to the second stage of labor (advanced labor). The HRA tool produces a numerical value representing low, medium or high risk. HRA risk categories from admission and advanced labor were correlated with intrapartum quantitative blood loss (QBL) using the Mann-Whitney U test. HRA scores were categorized as low/medium vs. high and cross tabulation tables created to estimate HRA sensitivity and proportion of those with stage III PPH ( >1500mL QBL).

Results: During the study period, 587 postpartum hemorrhages were identified, of which 194 (33%) were stage III. Of admission HRA scores (n=486), 10.1% (n=49) scored as high risk. When assessed during advanced labor (n=291), 41.2% (n=120) scored as high risk.  Examining low, medium, and high HRA scores at both admission and advanced labor revealed no association with QBL (Table 1). The sensitivity and specificity of predicting stage III PPH using our HRA score on admission was 11.9% and 90.8%, whereas assessment during advanced labor demonstrated a sensitivity and specificity of 42.9% and 59.5%.

Conclusion: While our HRA tool did not predict QBL according to risk categories, it was highly specific for stage III hemorrhage when assessed on admission. These results suggest sufficient utility and benefit of our current HRA tool. Further work includes evaluation using our HRA tool at additional time points during labor, with the aim of increased preparedness and resource allocation for the identification and treatment of PPH.