New 2026 ISTH Management of Type 2B von Willebrand Disease in Pregnant and Postpartum Women Guidance

The International Society on Thrombosis and Haemostasis (ISTH) recently released consensus-based guidance on managing pregnant and postpartum women with type 2B von Willebrand disease (VWD), a rare but notable form of VWD that affects a small percentage of patients. ISTH's clinical guidance document, Management of Women with Type 2B von Willebrand Disease During Pregnancy and Postpartum helps address the lack of evidence based guidance for this patient population. The guidance features three key sections: Diagnosis and Prenatal Counseling, Monitoring and Management During Pregnancy, and Management of Delivery and Postpartum Care.

Of the three sections, the bulk of the guidance focuses on managing delivery and postpartum care, with a total of 15 guidance statements included. The other sections on diagnosis and prenatal counseling and monitoring and management during pregnancy have six and four statements respectively. 

The following look at all the included guidance statements are divided into those three categories, and aggregated for your convenience. Consult the full-text version of the ISTH guidance for the most thorough look at the following statements.

ISTH Guidance Statements on Managing Type 2B VWD in Pregnant/Postpartum Women

Diagnosis and Prenatal Counseling

• In girls and women with abnormal initial VWF tests suggestive of type 2B VWD, we advise that the diagnosis be established as recommended by ASH ISTH NHF WFH 2021 guidelines, ideally before becoming pregnant. 
• We suggest that type 2B VWD should be considered as a differential diagnosis in all pregnant women with unexplained and progressive thrombocytopenia.
• In women presenting during pregnancy with suspected type 2B VWD, we advise that the threshold to perform genetic testing may be lower than in the non-pregnant state to minimize misdiagnosis due to pregnancy-induced changes of hemostatic parameters. 
• We advise appropriate prenatal counselling by a multidisciplinary team (MDT) expert in VWD. Women should be informed about the inheritance pattern of the condition, risk of bleeding during pregnancy, delivery & postpartum, and the need for regular monitoring, and treatment. 
• We suggest that in women with type 2B VWD, hemoglobin and ferritin levels be checked regularly before and during pregnancy. Iron substitution must be introduced - when indicated- to avoid iron deficiency and/or anemia during pregnancy.
• We suggest that all women with type 2B VWD are a priori at high risk of bleeding during pregnancy and postpartum, irrespective of previous bleeding history. 

Monitoring and Management During Pregnancy

• When assessing bleeding risk, we suggest that laboratory test results should not to be evaluated individually. Combined low VWF levels & thrombocytopenia represents a higher risk than each alone. Thrombocytopathy, reported in association with some 2BVWD variants adds to the risk. 
• We suggest that plasma VWF and FVIII levels and platelet count should be monitored at the beginning of the pregnancy, at least once during the third trimester, close to delivery, and at least once in the first week after delivery. The frequency and timing of testing may be adapted as per clinical judgement.
• Due to the complexity of type 2B VWD, and the high risk of pregnancy-related bleeding events, we advise that labor and delivery should be managed by a MDT, in a specialized center with access to factor concentrates and blood products, including platelets. It is important to ensure that haemostasias advice and appropriate laboratory monitoring is readily available to the obstetric team. 
• We suggest that in women with type 2B VWD who experienced bleeding requiring VWF replacement therapy during pregnancy, subsequent prophylactic administration of VWF concentrate may be considered. The dosing, intervals of administration, and duration of prophylaxis are determined based on bleeding risk, clinical response, and VWF/FVIII levels. 

Management of Delivery and Postpartum Care

• We advise that a delivery plan should be formulated in the third trimester using a shared decision-making process with the patient and MTD members. If any changes in the delivery plan are required, it is essential that these are discussed with the patient, clearly documented, and communicated to all the MTD members. 
• We suggest that the mode of delivery mostly depends on obstetric indications. Delivery must be achieved with the least traumatic method to the baby, avoiding fetal blood sampling, fetal scalp monitoring, ventouse delivery, and mid-cavity forceps. We also advise avoidance of external cephalic version during pregnancy for breech presentation.
• We suggest that VWF-containing concentrate and blood products should be readily available during pregnancy, at the time of delivery, and postpartum for all women with 2B VWD. 
• The safe level of VWF and platelet count for neuraxial anesthesia in women with type 2B VWD is not known, and we suggest that the risk must be assessed individually. Intervention must be avoided if the VWF activity level is <50 IU/dL and/or platelet count <70x10^9/L. The trough levels of VWF activity during neuraxial catheter stay must be >50 IU/dL. The removal of the catheter needs approximately the same levels of VWF and platelet count as for its placement. 
• We advise that desmopressin to be avoided in women with type 2B VWD during pregnancy and postpartum due to the risk of causing/worsening thrombocytopenia.
• We suggest that both laboratory results and clinical scenarios must guide replacement therapy with VWF, FVIII, and platelets for delivery and postpartum. 
• We suggest that the targeted VWF activity and FVIII levels for delivery are ≥ 100 IU/dL. Trough VWF/FVIII level should be kept at ≥ 80 IU/dL during the first 3-5 days after vaginal delivery and during 5-7 days after C-section. Replacement therapy could be continued beyond this period if excessive bleeding or a significant risk of bleeding persists with an adjustment of treatment according to clinical circumstances. 
• We suggest that platelet transfusion be administered when the platelet count is <30x10^9/L at the start of vaginal delivery or <50x10^9/L in case of cesarean delivery. Repeated platelet transfusions may be needed to achieve counts >30x10^9/L during the first 3-5 days after delivery. 
• If there is excessive bleeding during delivery or postpartum despite correct VWF replacement, we suggest that platelet transfusion be administered to achieve a platelet count >50x10^9/L.
• We suggest that blood count, plasma VWF activity and FVIII levels should be checked at least once in the first 24h after delivery in all women with type 2B VWD. In women receiving VWF and/or platelet replacement therapy, levels must be regularly monitored during the entire treatment period.
• We suggest that women with type 2B VWD undergo individualized venous thromboembolism risk assessment. If pharmacologic thromboprophylaxis is indicated, it should be administered for the minimum necessary duration, with close clinical surveillance and appropriate laboratory monitoring of haemostatic parameters. 
• We advise the use of postpartum tranexamic acid according to the ASH ISTH NHF WFH 2021 guidelines which favor administration of tranexamic acid over not. Tranexamic acid may be given via the oral or IV route. The recommended oral dose is ~ 25mg/kg 3 times per day for 10 to 14 days or longer if blood loss remains heavy. Women who intend to breastfeed should be provided education about benefits and the safety of tranexamic acid during breastfeeding.
• In cases of excessive postpartum bleeding, we suggest immediate, concurrent haemostatic and obstetric assessment. Haemostatic therapy should be guided by bleeding phenotype and laboratory results, while obstetric evaluation should identify and manage obstetric causes of haemorrhage. 
• After discharge, we advise that the team should keep close contact with the patient until the resolution of lochia. In case of significant bleeding, the patient will need an immediate assessment at the obstetric and haemostasias centers undergoing to rule out / manage obstetric causes for bleeding. 
• If prenatal testing is not done, we suggest that screening for type 2B VWD in the neonate may be done using cord blood sampling. Until the diagnosis of type 2B VWD is excluded, vaccines must be given subcutaneously with the smallest gauge needle. Vitamin K should be given orally if there is the delay in the diagnosis or the diagnosis of type 2B VWD is confirmed. The drug may also be administered subcutaneously if appropriate formulation is available and approved. 

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