Ethinylestradiol 20 versus 30 μg combined with 150 μg desogestrel: a large comparative study of the effects of two low-dose oral contraceptives on the hemostatic system

Abstract

In a 6-month, randomized, double-blind study the effects of two combined oral contraceptives containing 150 μg desogestrel and either 20 or 30 μg ethinylestradiol on hemostatic parameters were investigated in 1633 healthy women. Compared with baseline, the 30 μg ethinylestradiol formulation increased prothrombin fragment 1 + 2 (+ 72.2%), D-dimer (+ 42.4%) and protein c activity (+ 6.1%), whereas antithrombin-III activity (-6.3%) and protein S activity (-19.7%) were decreased. The im Of the 20 μg ethinylestradiol formulation was associated with the same pattern of changes, hit with lower magnitude (F1 + 2 +61.1%, D-dimer +36.0%, antithrombin III -5.3%, protein C +4.6% and protein S -16.0%). The changes from baseline were significantly smaller in the 20 μg ethinylestradiol group for D-dimer, antithrombin III and protein S than in the 30 μg ethinylestradiol group (p = 0.019, p = 0.038 and p = 0.001, resoectively). One woman with a combined deficiency of proteins C and S developed deep venous thrombosis while using the 20 μg ethinylestradiol formulation. Use of both formulations was associated with a shift of the coagulation—fibrinolysis balance to an enhanced fibrin-generating and fibrin-degradating activity. The less-pronounced effect on hemostasis with the 20 μg ethinylestradiol preparation is reassuring with regard to thromboembolic risk in general. However, women with coagulation inhibitor deficiency should be advised not to use oral contraceptives.

Key Words:

• Okal Contiraceptives
• Desogestrel
• Ethinylestradiol
• Hemostasis
• Coagulation Inhibitors