Postpartum hemorrhage (PPH), characterized by excessive bleeding following childbirth, remains one of the foremost causes of maternal mortality worldwide. Despite advances in obstetric care, its incidence poses a persistent threat, especially in high-resource countries like the United States, where maternal mortality rates have paradoxically increased over recent decades. Central to combating this challenge is the early detection and rapid management of hemorrhage, areas where innovative diagnostics such as viscoelastic testing (VET) could revolutionize clinical practice. This real-time blood clotting assessment tool offers the potential to transform how clinicians respond to obstetric bleeding, yet it remains underutilized in American maternity care settings.
Viscoelastic testing is a sophisticated hematological assay that evaluates the dynamic properties of blood clot formation, stability, and dissolution, providing a comprehensive picture of coagulation in real-time. Unlike traditional laboratory coagulation tests, which offer static and often delayed snapshots, VET delivers rapid bedside insights into the functional status of a patient’s hemostatic system. By analyzing parameters such as clot initiation time, clot strength, and fibrinolytic activity, VET enables clinicians to discern the precise deficiencies—be they platelet dysfunction, plasma coagulation factor deficits, or hyperfibrinolysis—that contribute to bleeding. This information directs targeted transfusion strategies, differentiating when to administer platelets, plasma, cryoprecipitate, or whole blood, thereby optimizing resource use and patient outcomes.
Although the utility of viscoelastic testing is well documented in cardiac surgery, trauma, and orthopedic procedures, its application in obstetrics, particularly for postpartum hemorrhage, is less established. The Blood-Brain Barrier Institute’s Southern California Evidence Review Center recently released a comprehensive scoping review, analyzing 156 studies that collectively underscore the promise of VET in maternity care but simultaneously highlight the scarcity of high-quality randomized controlled trials (RCTs) in this domain. The review, commissioned by the Patient-Centered Outcomes Research Institute (PCORI), also integrated perspectives from patients, healthcare practitioners, and policymakers to elucidate barriers hindering the widespread adoption of VET in U.S. obstetric practice.
One of the critical challenges identified by the review is the rarity of severe postpartum hemorrhage events, which complicates the design and implementation of large-scale clinical trials. Because PPH incidents are infrequent yet acutely critical, longitudinal data collection across multiple centers is necessary to generate statistically robust evidence. Moreover, variations in hospital protocols and blood management practices create heterogeneity that complicates the standardization of VET utilization. The researchers advocate for a coordinated, multi-center randomized trial framework, employing standardized VET protocols that would produce more definitive insights into the effectiveness and optimal implementation of this technology across diverse obstetric populations.
From a technical perspective, viscoelastic testing systems operate by measuring the viscoelastic properties of clotting blood using either rotational thromboelastometry (ROTEM) or thromboelastography (TEG). These devices apply mechanical stress to a blood sample and quantify the resistance and elasticity of the developing clot over time. The dynamic curves produced inform clinicians not only about the presence of coagulation abnormalities but also about their nature and severity. Such granularity is particularly valuable in PPH management, where rapid decision-making is crucial to prevent deterioration into hemorrhagic shock and multi-organ failure. The bedside availability of VET, requiring only small blood samples and delivering results within minutes, enhances clinical responsiveness in acute obstetric emergencies.
Despite these technological advances, the uptake of VET in obstetric settings has been hampered by economic and organizational impediments. Setting up VET-capable laboratories involves significant initial investment in equipment procurement, staff training, and integration into clinical workflows. Hospitals must weigh these costs against the prospective benefits, which, though compelling, remain insufficiently quantified in the obstetric context. Critics also point to the lack of standardized treatment algorithms derived from VET readouts, leading to uncertainty about clinical decision-making thresholds. Addressing these concerns requires both economic evaluations and protocol development based on rigorous clinical research and expert consensus.
Beyond survival, the adoption of viscoelastic testing carries important implications for healthcare equity and cost-effectiveness. Postpartum hemorrhage disproportionately affects marginalized populations, including Black women and those residing in rural areas, who face limited access to timely and precise obstetric interventions. Implementing VET technology has the potential to ameliorate these disparities by enabling more rapid diagnosis and personalized treatment at the point of care. Economically, by delineating exact transfusion needs, VET can minimize the unnecessary use of costly blood products, such as whole blood, and reduce wastage, ultimately translating into cost savings for healthcare systems burdened by rising expenditures.
The current evidence situation echoes broader debates on medical technology adoption, where the urgency of clinical need coexists with an imperfect evidence base. Researchers leading the review referenced the analogy of parachute use—widely accepted despite the absence of RCTs—emphasizing the logic of benefit over voluntary evidence accumulation. In the context of obstetric hemorrhage, the potential for VET to save lives provides a powerful argument for its phased integration into clinical practice, even as studies continue. This perspective advocates for a paradigm shift, accepting best-available evidence alongside rigorous ongoing research to hasten access to life-saving diagnostics.
Clinicians and hospital administrators contemplating VET incorporation must also consider workforce implications. Training physicians, nurses, and laboratory technicians in interpreting VET results and adapting treatment strategies is critical for effective deployment. Interdisciplinary collaboration becomes indispensable, as obstetricians, anesthesiologists, hematologists, and transfusion medicine specialists need to establish unified protocols. Simulation-based education platforms may accelerate proficiency, reducing cognitive load during actual hemorrhagic crises. Furthermore, integrating VET data into electronic health records can facilitate longitudinal monitoring and quality improvement initiatives.
The review authors encourage policymakers to prioritize funding for multi-center clinical trials that could solidify evidence-based guidelines. They highlight that protracted ambiguity surrounding VET standards has contributed substantially to its slow adoption. Clear clinical criteria defining when VET should be applied during labor and delivery—and specific thresholds for intervention based on test results—would catalyze uniformity in practice. This, in turn, would empower payers and regulators to endorse VET reimbursement, incentivizing hospitals to invest accordingly.
Innovations in viscoelastic testing hardware and software are underway, aiming to create more compact, user-friendly, and automated devices suitable for the obstetric unit environment. Advances such as improved sensor technology and artificial intelligence algorithms for interpreting complex coagulation patterns promise to enhance diagnostic accuracy and speed further. These developments could overcome current barriers related to cost and operator skill, making VET a routine component of obstetric hemorrhage management in the near future.
The synthesis of clinical evidence, expert insights, and patient experience contained in this landmark review serves as a clarion call to the medical community. Postpartum hemorrhage, though uncommon, carries catastrophic consequences, and viscoelastic testing represents a technological breakthrough with the potential to save countless lives. Through coordinated research efforts, protocol standardization, and policy advocacy, VET could become integral to obstetric care worldwide, shifting the paradigm from reactive to proactive management of maternal bleeding complications.
The path ahead will demand investment, collaboration, and iterative learning but the stakes could not be higher. Maternal mortality is a human tragedy that modern medicine can increasingly prevent. Viscoelastic testing embodies a scientific and clinical leap forward, bridging laboratory innovation and bedside care with the promise of timely, precise intervention. As the evidence base grows and health systems embrace this technology, the vision of safer childbirth can move closer to reality for women across the globe.
Subject of Research: People
Article Title: Viscoelastic testing in postpartum obstetric hemorrhage: a scoping review commissioned by the Patient-Centered Outcomes Research Institute (PCORI)
News Publication Date: 25-Aug-2025
Web References:
- Southern California Evidence Review Center
- Keck School of Medicine of USC
- International Journal of Obstetric Anesthesia article
- PCORI full report and issue brief
References:
Hempel, S., Janzen, C., et al. (2025). Viscoelastic testing in postpartum obstetric hemorrhage: a scoping review. International Journal of Obstetric Anesthesia. DOI: 10.1016/j.ijoa.2025.104763
Keywords:
Pregnancy complications, Obstetrics, Bleeding, Blood transfusion, Plasma, Platelets, Childbirth
