Hemostatic system changes induced by 50 micrograms and 30 micrograms estrogen/progestogen oral contraceptives. Modification of estrogen effects by levonorgestrel
Sabra, A.; Bonnar, J.
Journal of Reproductive Medicine 28(1 Suppl): 85-91
1983
ISSN/ISBN: 0024-7758 PMID: 6834350 Document Number: 207804
Three oral contraceptive preparations were compared for effects on blood coagulation, fibrinolysis and platelet function in a total of 86 healthy young women. Two of the preparations contained 30 .mu.g ethynyl estradiol combined with levonorgestrel or norethindrone acetate, and the 3rd contained 50 .mu.g mestranol and norethindrone. Tests were conducted before use of the agents, at intervals over 48 wk use and after discontinuation. This study showed that the changes in coagulation activity and fibrinolysis were largely related to the dose of estrogen in the contraceptive preparation; the smallest changes occurred with the low-dose (30 .mu.g) preparations. Changes occurring in certain coagulation factors and inhibitors were significantly smaller in the preparation containing 30 .mu.g of ethynyl estradiol combined with levonorgestrel, sugesting that the progestogen used in these combination oral contraceptives modifies the estrogen effects.