Careful monitoring and multidisciplinary management can ensure good outcomes for women with von Willebrand’s disease during pregnancy, labour and post-partum, according to Associate Professor Paula James from Queen’s University in Kingston, Ontario.
“Pregnancy is a time a profound physiologic change, normally involving major alterations in haemostatic factors which aim to prevent ante-partum and post-partum haemorrhage,” she said.
“This normally includes progressive increases in levels of von Willebrand factor (VWF) and factor VIII, which peak around labour and delivery.
“These adaptive changes also occur in women with non-severe von Willebrand disease (VWD), often resulting in normal levels of the factors despite the disease.
“But even if the levels normalise, women with VWD have an increased risk of complications during labour, delivery and in the weeks post-partum, so comprehensive management is essential to ensure the health of the mother and the child.”
Professor James said rates of bleeding in women with more severe VWD treated with a combination of VWF and factor VIII had up to three times the rate of bleeding in each trimester compared to healthy women, most markedly in the first trimester, as well as elevated rates of primary and secondary post-partum haemorrhage.
“While post-partum bleeding usually settles within a week for healthy women, it often persists for three or four weeks in women with VWD,” she said.
Her approach to management during pregnancy commences with measuring VWF and factor VIII as early as possible in pregnancy (in practice, usually at about 12 weeks) and again at week 32, and arranging review by a maternal/fetal medicine specialist .
“For the majority of patients who normalise these two markers during pregnancy, delivery in a local hospital is acceptable, but we cannot endorse a home birth,” Professor James said. “Epidural anaesthesia has been shown to pose little extra risk in these patients.”
She offers antifibrinolytic therapy with tranexamic acid to reduce post-partum bleeding, commencing after labour and continuing until bleeding stops, but with a review if bleeding persists at three weeks.
Women with more severe VWD and low levels of VWF and factor VIII in late pregnancy should be admitted to hospital and usually induced, to facilitate their intensive management.
Replacement of VWF and factor VIII can be delivered as bolus therapy or a continuous infusion, but the target levels are still very uncertain, and post-partum tranexamic acid is essential.