ASH and ISTH Publish New Clinical Practice Guidelines on Anticoagulant Prophylaxis in Pediatric Patients at Risk of Blood Clots

Recommendations outline best practices for preventing increasingly common, life-threatening complication in children

(WASHINGTON, Apr. 8, 2026) — The American Society of Hematology (ASH) and the International Society on Thrombosis and Haemostasis (ISTH) released comprehensive clinical practice guidelines on anticoagulant prophylaxis in non-cardiac pediatric patients at risk of venous thromboembolism (VTE). The guidelines were developed by an expert panel following a rigorous review process and published in ASH’s peer-reviewed journal, Blood Advances.

“This patient group is often among the most vulnerable and medically complex we treat, and clinicians have long lacked clear guidance on how to best care for them,” said ASH President Robert Negrin, MD. “These guidelines mark an important step in establishing clinical consensus to improve care and outcomes for children facing serious, life-threatening conditions. The Society is pleased to have collaborated with ISTH on this urgently needed project.”

VTE, or the formation of blood clots in veins, has become more common in pediatric patients over the past few decades, particularly among children who are hospitalized or have a chronic condition like cancer, which can lead to significant short- and long-term complications. Hospital-acquired VTE is the second most common cause of preventable harm in children, yet there has been little consensus on which patients should receive preventive care and what that care should involve.

“The ISTH is proud to partner with ASH on the important joint guidelines addressing venous thromboembolism in pediatric patients,” said ISTH President Pantep Angchaisuksiri, MD. “This collaboration reflects a shared commitment to advancing evidence-based care and provides clinicians with the tools to better treat and prevent blood clots in children worldwide.”

Grounded in the latest research, the guidelines were developed by a multidisciplinary expert panel as well as a lived experience expert, and present twelve recommendations and two good practice statements on administering anticoagulant prophylaxis, or preventive care, to children at risk of developing VTE. The guidelines include:

• Conditional recommendations suggesting no anticoagulant prophylaxis in children with solid cancer, trauma, or a critical illness
• Conditional recommendations suggesting anticoagulant prophylaxis in children who have antiphospholipid syndrome or are on long-term total parenteral nutrition
• Counsel on administering anticoagulant prophylaxis in patient subgroups including children with acute lymphoblastic leukemia or lymphoma, a central venous access device, or who have recently undergone surgery

Additionally, the guidelines encourage institutions to develop protocols for managing interruptions to therapy, particularly for those undergoing lumbar puncture or spinal anesthesia procedures. They also highlight the need for further research to develop VTE risk assessment models for this population and to evaluate the safety and efficacy of prophylaxis across different pediatric subgroups.

“Prior to the development of these clinical guidelines, much of the data we referenced for VTE prevention in pediatric patients was extrapolated from adults, whose risk profiles are generally less varied and complex,” said Marisol Betensky, MD, MPH, associate professor of pediatrics in the division of hematology at Johns Hopkins University School of Medicine, pediatric hematologist in the Johns Hopkins All Children’s Cancer & Blood Disorders Institute, and co-chair of the guidelines. “These guidelines provide physicians with an evidence-based framework to make decisions about VTE prophylaxis for children.”

Additional guidelines resources, including visual summaries, and teaching slides, can be accessed at hematology.org/VTE.

ASH and ISTH previously developed revised clinical practice guidelines for pediatric VTE treatment.

About the American Society of Hematology

The American Society of Hematology (ASH) (hematology.org) is the world’s largest professional society of hematologists dedicated to furthering the understanding, diagnosis, treatment, and prevention of disorders affecting the blood. Since 1958, the Society has led the development of hematology as a discipline by promoting research, patient care, education, training, and advocacy in hematology. Join the #Fight4Hematology by visiting hematology.org/fight4hematology.

The Blood journals (https://ashpublications.org/journals) are the premier source for basic, translational, and clinical hematologic research. The Blood journals publish more peer-reviewed hematology research than any other academic journals worldwide.

About the International Society on Thrombosis and Haemostasis

Founded in 1969, the ISTH is the leading international medical and scientific professional organization dedicated to advancing the understanding, prevention, diagnosis and treatment of conditions related to thrombosis and hemostasis. The ISTH professional membership community includes more than 7,000 clinicians, researchers and educators from more than 120 countries working together to advance science and improve clinical care around the world. Among its highly-regarded activities and initiatives are education and standardization programs, research activities, meetings and congresses, clinical and laboratory practice guidance and guidelines, peer-reviewed publications, expert committees and World Thrombosis Day on 13 October. Learn more at www.isth.org.

Contact ASH:
Claire Whetzel, 202-629-5085
[email protected]

Contact ISTH:
Barbara Krolak
[email protected]