Effect of various estrogen treatment schedules on antithrombin III levels

Antithrombin III levels were determined in 18 normal indiviuals of both sexes, 24 pregnant women (at term), 20 patients treated with oral contraceptives and 21 postmenopausal patients treated with Premarin. There was no sex difference in antithrombin III levels in the untreated control group. Pregnant women at term had the lowest levels of antithrombin III. The second lowest values were exhibited by women on oral contraceptives. Both of these groups differed significantly (p less than 0.05) from the controls. Premarin treated postmenopausal women had somewhat lower levels of antithrombin III than controls but these were statistically not significant.