271 Impact of von willebrand disease on maternal morbidity at time of delivery

Abstract

The impact of von Willebrand disease (VWD) on pregnancy has been narrowly characterized beyond an association with increased hemorrhage risk and need for transfusion. We sought to evaluate the relationship between VWD and severe maternal morbidity (SMM) at time of delivery. Using National Inpatient Sample data from 2007-2013, we identified delivery admissions for women with and without a diagnosis of VWD (ICD-9-CM 286.4). We examined the rates of SMM as defined by the Centers for Disease Control and Prevention for these two groups, both including then excluding blood product transfusion. Poisson regression evaluated the association between VWD and SMM controlling for maternal comorbidities using a validated index (low: 0, moderate: 1-2, high: >2) and mode of delivery. Data analysis was weighted to provide national estimates. We identified 5.7 million delivery admissions during this study period, of which 2,357 (0.04%) carried a diagnosis of VWD. The rate of SMM was significantly higher in women with VWD compared to women without VWD (6.6% vs 1.5%), and this persisted after excluding transfusion (1.31% vs 0.6%, both p<0.001). The incidence rate ratio after adjusting for maternal comorbidities and mode of delivery for overall SMM was 4.08 (95% CI 3.80-4.38) and with transfusion excluded was 1.97 (95% CI 1.68-2.31, both p<0.001). Several individual SMM indicators were associated with VWD including anesthesia complications, transfusion, air and thrombotic embolism, disseminated intravascular coagulation, acute respiratory distress syndrome and hysterectomy (Figure 1). Women with VWD experience four-fold the incidence of SMM at delivery compared with unaffected women. Even with blood product transfusion excluded, VWD doubles the incidence rate of SMM. Our study likely underestimates the complete impact of VWD on maternal morbidity as we focused only on the delivery admission. Further studies on the association of VWD with non-transfusion related SMM are needed to better inform delivery planning and postpartum care for women with VWD.