Pregnancy loss in individuals with von Willebrand disease and unspecified mucocutaneous bleeding disorders: A multicentre cohort study.

Background: While bleeding around pregnancy is well described in von Willebrand disease (VWD), risk of pregnancy loss is less certain. We aimed to describe the frequency of pregnancy loss in females with VWD, compared with those with a similar mucocutaneous bleeding phenotype and no VWD, or compared with non-bleeding disorder controls.

Methods: Female patients were consecutively approached in 8 specialty bleeding disorder clinics between 2014-2023. The VWD group was defined as having VWF:Antigen (Ag) and VWF:Activity (Act) levels, each <0.50 IU/mL on ≥2 occasions, and a Condensed MCMDM-1 score of ≥4. The non-VWD mucocutaneous bleeding disorder group had VWF levels ≥0.50 IU/mL on ≥2 occasions and a MCMDM-1 score ≥4. A non-bleeding disorder control group was recruited in pregnancy from a low-risk maternity clinic.

Results: There were 150 females in the VWD group, 145 in the non-VWD mucocutaneous bleeding disorder group, and 137 in the control group. There was a similar frequency of individuals with ≥1 loss in the VWD group (45.3%, 68/150), the non-VWD group (56.6%, 82/145) (-11.2%, 97.5% CI -24.2, 1.8%), and the non-bleeding disorder control group (37.2%, 51/137) (8.1%, 97.5% CI -4.9%, 21.1%). Using a logistic regression, the odds ratio of pregnancy losses in the VWD group versus non-VWD group was 0.94 (95% CI 0.65, 1.36). All groups experienced more recurrent losses compared to the literature.

Conclusions: There was no statistically significant difference in risk of pregnancy loss between females with VWD, females with a similar mucocutaneous bleeding phenotype, and with non-bleeding disorder controls.