ANTICOAGULATION IN PREGNANCY IN PATIENTS WITH CARDIAC VALVE PROSTHESIS

The use of oral anticoagulation in pregnancy is controversial due to the risk of embryopathy (1° trimester), intracerebral hemorrhages (2° trimester) and the use of heparin is associated with a high morbidity due to abortion and prematurity. The outcome of 50 pregnancies in 30 patients with heart prosthesis was evaluated. Acenocoumarol and aspirin 500 mg/daily were given in all the patients since their surgery. Anticoagulant doses were controlled with prothrombin time (PT) performed with human brain thromboplastin and APTT. The therapeutic range for the PT was the International Calibrated Ratio (ICR) 2.5 to 3.5. In 12 pregnancies, oral anticoagulation was replaced by subcutaneous heparin in the first trimester; the same policy was followed before delivery except in 4 cases. The foetal loss was 34% with equal distribution along the three trimesters and no correlation with excess of anticoagulation. The incidence of hemorrhage was 6% and the rate of cerebral embolism was also 6% (3 on to 50). Two of the three episodes of embolism appeared while patients were on heparin. A total of 33 normal babies were born (66%). No typical warfarin embryopathy was found and no perinatal mortality was observed. A slight reduction in the anticoagulant doses was necessary in almost half of the cases.

As the rate of foetal loss with heparin is not better than with oral anticoagulants and the incidence of embolism is higher, we are doubtful about the indication of subcutaneous heparin in the first trimester considering our absence of malformations with the acenocoumarin.