Observations during the treatment of antithrombin-III deficient women with heparin and antithrombin concentrate during pregnancy, parturition, and abortion

Antithrombin III and Platelets during the Normal Menstrual Cycle and in Women Receiving Oral Contraceptives Low in Oestrogen

“…While the presence of AT-III in blood constitutes one of the major mechanisms for protection against intravascular coagulation, there is no evidence per sc that a reduced level of AT-III is followed by coagulation, but rather that coagulation will occur more readily during exposure to thrombogenic situations in which thrombin formation is enhanced [10,13,20]. New findings suggest that thrombogenic exposure causes AT-III to be temporarily removed from the circulation by the reversible binding to the surfaces of injured cells and platelets [13,21], thereby preventing an activa tion of the coagulation process followed by formation of activated factor X and thrombin.…”

“…New findings suggest that thrombogenic exposure causes AT-III to be temporarily removed from the circulation by the reversible binding to the surfaces of injured cells and platelets [13,21], thereby preventing an activa tion of the coagulation process followed by formation of activated factor X and thrombin. Similarly, there is no evidence that oral contraceptive hor mones actually induce thrombus formation, so that this could not be the mechanism by which the levels of AT-III are caused to decrease.…”

“…Few reports [8,9] deal with possible variations in the platelet number associated with the use of oral contraceptives, but recent observations on patients receiving AT-III concentrate have indicated that fluctuations in the number of platelets tended to parallel fluctuations in the level of plasma AT-III during periods of thrombo-embolism or thrombogenic exposure [10][11][12][13],…”

Anticoagulant Effect of Unfractionated Heparin in Antithrombin-Depleted Plasma in vitro

“…Some authors mention a decreased anti coagulant potential of heparin in antithrom bin deficiency states [4][5][6][7][8], while others found no influence of low antithrombin concentra tion on the effect of heparin [9,10]. In the lit erature we found no consensus on the need to combine antithrombin concentrate with hep arin for thrombosis prophylaxis during preg-nancy, puerperium and after surgery [7,[11][12][13].…”

Letter to the editor: Prophylaxis of thromboembolism during pregnancy in hereditary AT‐III deficiency

“…Combining our results with those of others who have used similar regimen [4,6] shows that none of the nine AT-I11 deficient patients had thromboembolism and nine healthy infants were born. Results using subcutaneous heparin throughout pregnancy are inferior with 6 of 24 reported patients developing thromboembolism [3,5,7]. Administration of sodium warfarin may increase AT-I11 levels, resulting in a better antithrombotic effect than heparin.…”