[Anticoagulant therapy during pregnancy in patients with mechanical valvular prostheses].

Anticoagulant therapy (heparin or oral anticoagulants) during pregnancy in patients with mechanical valvular prostheses should take into consideration the respective risks of the usage of these two products: thromboembolic for the mother, congenital malformations for the children and haemorrhagic for them both. Basically, heparin therapy is useful by limiting the risk of foetal complication, but it increases maternal risk, especially related to thromboembolism. The risks of oral anticoagulants are concentrated in the second half of the first trimester (coumarin-related embryopathies) and in the peri-partum period (maternal and foetal haemorrhage).