The “500 moment”: a novel obstetric safety algorithm reduces the risk of significant postpartum hemorrhage

To evaluate the efficacy of a multimodal obstetric hemorrhage prevention algorithm in lowering the obstetric hemorrhage rate at a tertiary care center to under the national rate of 3%. A multidisciplinary team convened to create an obstetric hemorrhage prevention algorithm, which we hypothesized would decrease obstetric hemorrhage rates by enabling prompt treatment of postpartum bleeding. The algorithm included a team-based timeout, treatment recommendations, and practice changes dependent on patient-specific risk factors, etiology of bleeding, and blood loss amounts. A specific treatment trigger, called “the 500 moment” was a key component of the algorithm. Our primary outcome was obstetric hemorrhage rate. The retrospective chart review began in November 2022, after which the algorithm was introduced to the care team. Data review continued through April 2024. The study included 9534 patients who had either vaginal or cesarean deliveries, of which 4062 were in the pre-intervention group and 5472 were in the post-intervention group. At the time of the algorithm’s implementation, the obstetric hemorrhage rate was 9.3% (29 per 313 births). After the full adoption of the multimodal algorithm, the obstetric hemorrhage rate hit a maximum of 7.3% (24 per 328 births) in March 2023 and a minimum of 1.2% (4 per 322 births) in April 2024. The average quantitative blood loss decreased significantly from 408 mL before implementation to 367 mL after implementation ( P < .0001), and this change was more pronounced for cesarean deliveries than vaginal. Our algorithm favorably impacted obstetric hemorrhage rates at our hospital.