Heparin-dipyridamole (Persantin) treatment in pregnancy: effect on blood coagulation parameters

13 patients suspected of intra-uterine growth retardation (IUGR) were treated with a combination of heparin and dipyridamole. The effect of this anticoagulant therapy on platelet count, clot retraction, fibrinogen degradation products, antithrombin III (AT-III), plasminogen, fibrinogen and platelet aggregation induced by epinephrine, ADP, collagen and ristocetin has been examined. All parameters were measured both before and after treatment with heparin-dipyridamole. The results were compared with the results from a control group consisting of pregnant women of the same gestational age using no medication and not suspected of IUGR (n = 17). A significant decrease in the clot retraction was observed in patients with IUGR as compared to pregnant controls (p less than 0.05). A significant decrease in the AT-III level (p less than 0.01) and a significant increase (p less than 0.01) in the fibrinogen level were observed after heparin-dipyridamole treatment of patients suspected of IUGR. We conclude that the combination of a high fibrinogen and a low AT-III level will cause an increased risk for the development of thrombosis upon termination of treatment. We also observed that heparin clearance is increased during pregnancy.