Von Willebrand Factor in Pregnancy (VIP) Study

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