Current State and Future Direction of Postpartum Hemorrhage Risk Assessment

Abstract

In the United States, postpartum hemorrhage is a leading preventable cause of maternal mortality and morbidity. To reduce morbidity from postpartum hemorrhage, risk assessment is an important starting point for informing decisions about risk management and hemorrhage prevention. Current perinatal care guidelines from the Joint Commission recommend that all patients undergo postpartum hemorrhage risk assessment at admission and after delivery. Three maternal health organizations—the California Maternal Quality Care Collaborative, AWHONN, and the American College of Obstetricians and Gynecologists’ Safe Motherhood Initiative—have developed postpartum hemorrhage risk-assessment tools for clinical use. Based on the presence of risk factors, each organization categorizes patients as low-, medium-, or high-risk, and ties pretransfusion testing recommendations to these categorizations. However, the accuracy of these tools' risk categorizations has come under increasing scrutiny. Given their low positive predictive value, the value proposition of pretransfusion testing in all patients classified as medium- and high-risk is low. Further, 40% of all postpartum hemorrhage events occur in low-risk patients, emphasizing the need for early vigilance and treatment regardless of categorization. We recommend that maternal health organizations consider alternatives to category-based risk tools for evaluating postpartum hemorrhage risk before delivery.

Comparison of Clinical Efficacy and Safety between Misoprostol and Oxytocin in the Prevention of Postpartum Hemorrhage: A Meta-Analysis

“…Related studies show that maternal deaths due to postpartum hemorrhage account for 80% of the total number of maternal deaths, and the important cause of postpartum hemorrhage is uterine contraction weakness [ 2 ]. In recent years, with the continuous development of obstetric medical technology, although the mortality rate of maternal direct death from postpartum hemorrhage is decreasing year by year, postpartum hemorrhage is still the first cause of maternal death [ 3 , 4 ].…”

Oxytocin receptor single nucleotide polymorphism predicts atony-related postpartum hemorrhage

“…While risk factors are well-documented from descriptive studies (i.e. longer second stage labor, infant macrosomia, oxytocin administration during labor); an estimated 40% of PPH occurs during births without these commonly-noted risk factors [ 8 , 19 , 61 – 64 ] as assessed with available screening tools. A reason for this inaccuracy in risk assessment is due to the fact that PPH is a diagnosis only made after a high cumulative blood loss has occurred.…”

Intrapartum Risk Factors and Prediction of Obstetric Hemorrhage–Related Morbidity

“…13 Although recent research has shown that intrapartum factors are valuable in predicting OBH related severe morbidity and mortality, none of these validation studies have determined how a dynamic approach, with reassessment after admission and inclusion of intrapartum risk factors, may modify risk and, ultimately, clinical decision making. 13,14 We seek to assess our dynamic hemorrhage risk assessment tool, which was built to predict hemorrhage and transfusion using risk factors in the literature, reflected also in recommendations by the CMQCC, the Association of Women's Health, Obstetric and Neonatal Nurses (AWHONN), and the Safe Motherhood Initiative (Table 1). 4,6,7 We hypothesize that inclusion of intrapartum risk factors immediately prior to delivery (pre-delivery) increases the sensitivity of…”

“…In the context of this study, which demonstrates increased predictability of OBH-T in high-risk patients with inclusion of intrapartum factors, we recommend that further studies consider examining blood preparation recommendations for high hemorrhage risk patients using data that integrates intrapartum factors in risk assessment. 13 The first strength of this study is the population, which is highly racially and ethnically diverse, and in a safety-net hospital setting. Notably, previous validation studies have not examined this population and hospital setting.…”

“…Investigators are now creating these predictive models via statistical and machine learning tools in order to create risk assessment with individualized probabilities. 13 For example, Venkatesh et al described machine learning and statistical models that can accurately predict OBH based on data available on admission. 21 Given that our results suggest the dynamic nature of risk assessment for hemorrhage, we recommend that future work in predictive modeling consider incorporating intrapartum risk factors to change risk calculation both after admission and until delivery.…”