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Updated: Sep 26, 2025

Investigating von Willebrand Factor Pathophysiology Using a Flow Chamber Model of von Willebrand Factor-platelet String Formation
Published on: August 14, 2017
Von Willebrand Disease and Pregnancy
Muhammad Wasif Saif1, Carmen Allegra2
1National Cancer Institute-Naval Medical Center in Bethesda, Md.
Abstract:
A 26-year-old woman (gravida 1) was seen when she was 33½ weeks pregnant. She was healthy except for easy bruising, which had been a problem since childhood. The patient did not have nosebleeds or prolonged bleeding after toothbrushing, flossing, or minor cuts. Menarche had occurred at age 13, with a 28-day cycle. Her heavy menstrual periods usually lasted 7 to 10 days. She underwent tonsillectomy and adenoidectorny at age 7 and bilateral bunionectomy at age 20; hemorrhage did not occur after the operations. The patient did not smoke or abuse drugs or alcohol. She took no medications except for prenatal vitamins. Mild von Willebrand disease (vWD) had recently been diagnosed in her mother. Her father had anemia of unknown cause; his family history included thalassemia, and his father had Hodgkin disease that was diagnosed when he was 30 years old. Her 23-year-old brother was healthy and had no bleeding disorders. The patient appeared well-nourished and was in no distress. Vital signs were stable, and site was afebrile. Heart sounds were normal; lungs were clear. Her abdomen was soft and rumtender. There was no spine tenderness, mucosal bleeding, ocular hemorrhage, or skin bruising. Because of the patient's history of easy bruising and heavy menstrual bleeding and her mother's recently diagnosed vWD, testing for the disorder was ordered. Laboratory results revealed von Willebrand factor (vWF) antigen activity of 75 U/dL, activated partial thromboplastin time (aPTT) of 32 seconds, factor VIII activity of 100%, and bleeding time of 9 minutes. (Normal values are vWF antigen level, 50 to 200 U/dL; aPTT) 20 to 32 seconds; factor VIII activity, 60% to 150%; and bleeding time, 5.5 minutes.) A ristocetin-induced platelet aggregation test did not show aggregation at tow concentrations of ristocetin, and vWF multimers showed a normal distribution. These laboratory data suggested that the patient had type 1 vWD. She was closely monitored during the rest of her pregnancy. At full term, the patient went into labor. About 1 to 2 hours before the delivery, she was given intravenous desmopressin at a dosage of 0.3 μg/kg in 50 mL of saline over 30 minutes. When vaginal bleeding (approximately 150 mL) occurred on postpartum day 3, the patient was given nasal desmopressin and advised to limit her physical activity. No excessive bleeding occurred thereafter.
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