Presented September 3, 2025 at the 2025 APSF Stoelting Conference on “Transforming Maternal Care: Innovations and Collaborations to Reduce Morbidity and Mortality”
SUMMARY
Lisa Leffert, MD’s presentation addresses Venous Thromboembolism (VTE), a high-risk complication and a leading cause of maternal mortality. Pregnancy creates a perfect storm for VTE, increasing risk four to six times. The primary challenge is the lack of definitive evidence for VTE prevention, as clinical guidelines from major organizations (RCOG, Chest, ACOG) are highly discordant and show major variation in identifying which women should receive postpartum prophylaxis. Although data is insufficient to definitively prove the efficacy of routine prophylaxis, the current strategy focuses on pharmacologic prevention with low molecular weight heparin (LMWH) and continuous risk assessment (antepartum, peripartum, and postpartum). Anesthesia professionals must collaborate with obstetric teams to navigate the safety risks, particularly the timing of neuraxial anesthesia with anticoagulant administration.
Key Points:
- High-Risk Period
Pregnancy is a hypercoagulable state, increasing a woman’s risk for VTE by three to six times compared to a non-pregnant woman. The risk is four-fold higher with Cesarean delivery [01:11, 01:19]. - Discordant Guidelines
There is no consensus on VTE prophylaxis; guidelines from major bodies (e.g., ACOG, Chest, RCOG) lead to highly variable practice, with some recommending prophylaxis for 85% of women and others for only 1% of the same cohort [06:44, 07:24]. - Evidence Gap
Systematic reviews consistently conclude that current literature provides insufficient evidence to definitively prove whether or not postpartum pharmacologic prophylaxis reduces VTE rates [08:22, 08:44]. - Risk Assessment is Dynamic
VTE risk is not static. Assessment must be continuous, occurring antepartum, during hospitalization, at the time of a peripartum event, and postpartum [02:58, 03:17]. Risk factors are increasing over time, with three-quarters of postpartum women having at least one VTE risk factor [11:23, 11:53]. - Anesthesia and Anticoagulation
The risk of spinal/epidural hematoma for obstetrics patients is extremely low (approx. 1 in 200,000). For patients receiving low-dose thromboprophylaxis, the key is planned care and collaboration to adhere to recommended time delays (e.g., 12 to 24 hours for LMWH) before performing neuraxial anesthesia [13:01, 18:56].
ABOUT THE SPEAKER(S)
Lisa Leffert, MD
Professor and Chair of Anesthesiology,
Yale Medical School
Chief of the Obstetric Anesthesia Division,
Massachusetts General Hospital
Lisa Leffert, MD is the Nicholas M Greene Professor and Chair of Anesthesiology at Yale Medical School in New Haven, CT. She is a previous Past President of the Society for Obstetric Anesthesia and Perinatology (SOAP) and long-time Division Chief of the Obstetric Anesthesia Division at the Massachusetts General Hospital in Boston, MA. Leffert lectures nationally and internationally on diverse topics such as the anesthetic management of patients with neurologic disease and vulnerabilities, strategies for placing neuraxial anesthetics in patients with bleeding disorders. She has led an interdisciplinary effort to create a SOAP consensus statements on neuraxial anesthesia in the obstetric patient on thromboprophylaxis and higher dose anticoagulants and thrombocytopenia, worked collaboratively with ASRA on key guidelines, and currently leads the SOAP Research Network General Anesthesia Registry.
