Obstetric management in von Willebrand's disease: a report of 24 pregnancies and a reivesw of the literature.

The case records of 13 patients (24 pregnancies) with von Willebrand's disease (vWD) were studies rettospectively. The overall incidence of primary and secondary post-partum haemorrhage (PPH) was 15.8% and 25% respectively, all primary PPH occurring in tyre 2 discase (3/14 deliveries, 21.4%). The risk of primary PPH in type 2 patients who did not receive prophylactic factor VIII was 37.5% (3/8 deliveries). Factor VIII coagulant activity (VIII:C) and von Willebrand factor antigen (vWF:Ag) rose above bascline values by a factor of at least 1.5 during the pregnancy in most case. More severely affected patients were less likely to benefit significatntly. A baseline VIII:C of <15 iu/dl (4/14 cases) was predictive of a third trimester level of <15 iu/dl. Improvements in the von Willebrand factor activity were less marked. The baseline von Willebrand factor activity was <15 iu/dl in all patients with serial data, none of whom achieved a third-trimester von Willebrand factor activity of >50 iu/dl. The bleeding times were unaltered significantly in all but one of the cases, reflecting a general failure of the primary haemostatic defect to improve with pregnancy. The findings demonstrate that coagulation parameters do not universally improve in pregnancy in vWD, especially when preconception levels are low. The risk of primary PPH is generally higher in type 2 diseases. The level of factor VIII:C is not a good predictor of the risk of primary PPH in type 2 patients. Secondary PPH is a significatnt risk in both type 1 and type 2 patients.