Von Willebrand Factor in Pregnancy (VIP) Study

For pregnant women with von Willebrand disease (VWD) who by the third trimester do not have von Willebrand factor (VWF) or factor VIII (FVIII) levels > 50-100%, specific guidance is lacking for delivery planning for how high a VWF level should be achieved. Specifically, guidance is lacking on whether VWF replacement therapy should target a VWF minimum level in the 100-150% range, i.e., a range closer to the 200-250% levels observed in normal pregnancy.

This is a prospective, open-label, cohort study using Wilate VWF replacement therapy, trough or minimum VWF levels of 100-150% will be maintained for delivery in women with VWD whose third trimester VWF levels are <100%. This group is termed "non-correctors". Women with VWD whose third trimester VWF levels spontaneously rise to >100% will be assigned to the "corrector" group, and these women will not receive VWF replacement therapy. All patients will receive tranexamic acid for 14 days postpartum. Outcome parameters will be assessed for all patients.

The investigators or qualified research personnel will approach all consecutive pregnant VWD patients until 65 non-corrector patients have completed the study protocol, and up to 30 corrector patients have completed the study protocol. Patients with gestational week 34-38 von Willebrand factor activity (VWF:Act) or von Willebrand factor ristocetin cofactor (VWF:RCo), and/or Factor VIII procoagulant activity (FVIII:C) less than 100 percent will be used to assign patients to the non-corrector group. When VWF collagen binding (VWF:CB) laboratory monitoring can be performed, patients with an isolated VWF:CB type 2 defect can also be enrolled.

Rate of primary postpartum hemorrhage, severe postpartum hemorrhage, secondary postpartum hemorrhage will be measured. Safety and secondary laboratory measures will be assessed.

Inclusion criteria

• von Willebrand Disease (VWD) patients defined prepartum as Type 1 per National Heart, Lung, and Blood Institute (NHLBI) criterion of von Willebrand Factor (VWF) level less than 30 percent, or Type 2, or Type 3 VWD

or

• A diagnosis of VWD and VWF and Factor VIII (FVIII) levels obtained in gestational weeks 34-38 that determine enrollment in the non-corrector group:
• Patients with gestational week 34-38 VWF:Ag, VWF:Act (or VWF:RCo), or FVIII:C less than 100 percent will be enrolled in the non-corrector group. In patients with an isolated VWF:CB type 2 defect, VWF:CB less than 100 percent can also be determined as a non-corrector
• Patients with all VWF parameter levels greater than or equal to 100 percent self-corrected at gestational weeks 34-38 will be enrolled in the corrector group

Written informed consent from the patient prepartum, before gestational week 39

Exclusion criteria

• Presence of a clinical contraindication to receive wilate or tranexamic acid, as determined by the health care provider, such as a prior drug reaction
• Presence of other concurrent disorder of hemostasis, platelet dysfunction, or collagen disorders
• Presence of liver disease or renal disease, clinical suspicion or diagnosis of preeclampsia or eclampsia, HELLP syndrome, TTP, DIC, or other acquired vasculopathy or coagulopathy
• Age less than 18 years
• Inability of the local laboratory to monitor the VWF laboratory tests needed during the course of treatment to determine Wilate dosing adjustments