Von Willebrand Disease (VWD): Key Points
Classification and Inheritance
- Classification:
- Type 1: Partial quantitative deficiency of von Willebrand factor (VWF).
- Type 2: Qualitative defect in VWF.
- Type 3: Severe quantitative deficiency.
- Classification guides diagnosis, treatment, and counselling but has variable response to therapy and VWF gene mutation associations.
- Inheritance:
- Autosomal inheritance.
- Can be dominant or recessive, depending on VWD type.
- Genetic counselling is essential to address risks of transmission, penetrance, and expression variability.
Risks in Pregnancy to Mother and Baby
- Maternal Risks:
- Increased risk of antepartum, primary, and secondary postpartum haemorrhage (PPH).
- Women with low VWF levels (e.g., Type 1 <0.5 IU/ml by term, Type 2 or 3) face higher bleeding risks.
- Counselling:
- All women should receive counselling on bleeding risks during pregnancy and delivery.
Prepregnancy and Antenatal Management
- Pre-Conception:
- Assess bleeding phenotype, review diagnosis, and evaluate response to DDAVP.
- Multidisciplinary approach is critical.
- Testing:
- Check VWF antigen levels, activity, and factor VIII at booking, third trimester, and before invasive procedures.
- Management:
- Type 1 VWD with normal VWF levels: Managed in standard obstetric units.
- Types 2 and 3 or severe Type 1: Refer to high-risk centres with haemophilia expertise.
- Aim for VWF:RCo and factor VIII levels of ≥0.5 IU/ml for procedures.
- Treatment:
- Use DDAVP where possible, avoiding in pre-eclampsia. Restrict fluid intake post-DDAVP.
- For VWF replacement, use safe plasma-derived concentrates.
- Monitor levels post-treatment and after invasive procedures.
Intrapartum Management
- Timing:
- Administer treatment close to delivery and monitor pre-/post-treatment VWF and factor VIII levels.
- Additional Therapies:
- Tranexamic acid (oral or IV) for VWF <0.5 IU/ml or as sole therapy when clinically appropriate.
- Platelet transfusions may be needed for Type 2B VWD.
- Delivery Mode:
- Spontaneous vaginal delivery preferred unless obstetric indications suggest otherwise.
- Avoid fetal interventions like ventouse or midcavity forceps in at-risk fetuses (Types 2 or 3).
Analgesia and Anaesthesia
- Neuraxial Anaesthesia:
- Permitted in Type 1 with normalised VWF levels.
- Avoid in Type 2 unless VWF activity >0.5 IU/ml and defect corrected.
- Contraindicated in Type 3 and Type 2N unless factor VIII >0.5 IU/ml.
- Precautions:
- Discuss options with senior anaesthetist.
- Monitor for bleeding risks during catheter placement/removal.
- Limit intramuscular injections and NSAID use to cases with VWF and factor VIII >0.5 IU/ml.
Postpartum Management
- Monitoring:
- Maintain VWF and factor VIII levels >0.5 IU/ml for at least:
- 3 days post-uncomplicated vaginal delivery.
- 5 days post-instrumental delivery or caesarean section.
- Medications:
- Tranexamic acid: Standard dose 1 g 3–4 times/day for 7–14 days (or longer if needed).
- LMWH for thromboprophylaxis with corrected VWF:RCo and factor VIII levels.
- Awareness:
- Educate on risks of delayed bleeding.
- Monitor haemoglobin in severe cases (e.g., Type 3).
- VWF concentrate may be needed for 2–3 weeks postpartum.
Neonatal Management
- Testing:
- Include cord blood sampling for VWF activity in neonates at risk (Types 2 and 3).
- Vitamin K:
- Administer orally if VWF levels are normal; avoid intramuscular injection in at-risk neonates.
- Special Cases:
- For neonates with Type 3, consider cranial imaging and short-term prophylaxis with factor concentrate if significant trauma occurred during delivery.
References: RCOG Green-top Guidelines No. 71 (2017).
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