Hemorrhage risk score and peripartum quantified blood loss

Background: Risk assessment tools are used by clinicians to predict which patients might have excessive bleeding. We studied the association between a peripartum hemorrhage risk assessment score using peripartum quantified blood loss (QBL) among those with vaginal deliveries who are often at lower risk for peripartum hemorrhage.

Methods: In this retrospective analysis of 1221 patients with term vaginal deliveries at a public New York City hospital, the Association of Women's Health, Obstetric and Neonatal Nurses (AWOHNN) risk assessment tool was used to categorize patients as low risk, medium risk, or high risk for postpartum hemorrhage.

Results: Low-risk scores were present in 925 (75.8%) patients, medium-risk scores in 268 (21.9%) patients, and high-risk scores in 28 (2.3%) patients. Outcome variables consisted of QBL (M = 213.8, SD = 215.00 mL), QBL ≥ 500 mL (n = 89, 7.3%), and ratio of postdelivery hematocrit to predelivery hematocrit (M = 0.9, SD = 0.08). High-risk score (B = 0.14, SE = 0.07, P = 0.04) but not medium-risk score was significantly associated with increased QBL as compared to low-risk score. Body mass index (BMI) measured as a continuous variable was significantly associated with increased QBL (B = 0.004, SE = 0.002, P = 0.049). However, BMI measured as a categorical variable using the AWOHNN cutoff score of >35 was not significantly associated with QBL. AWOHNN score was not significantly associated with QBL ≥ 500 mL or with the ratio of postdelivery hematocrit with predelivery hematocrit.

Conclusion: We recommend revising the AWOHNN measure to better reflect medium risk and to consider a different approach for BMI use as part of the AWOHNN risk score.