The following is a summary of “Low Thrombin Generation in Users of a Contraceptive Containing Estetrol and Drospirenone,” published in the January 2023 issue of Endocrinology & Metabolism by Morimont, et al.

For a study, researchers sought to compare ethinylestradiol (30 or 20 mcg) paired with either 150 mcg of levonorgestrel or 3 mg of drospirenone with the new combination oral contraceptive comprising 15 mg of estetrol and 3 mg of drospirenone, depending on which is related with ethinylestradiol’s effect on thrombin production.

Data from the “E4/DRSP Endocrine Function, Metabolic Control, and Hemostasis Study” were gathered. The total population in the per-protocol set consisted of 34 participants in the estetrol/drospirenone arm, 28 subjects in the ethinylestradiol/drospirenone arm, and 24 subjects in the ethinylestradiol/levonorgestrel arm. Each patient had thrombograms and thrombin production parameters (lag time, peak, time to peak, endogenous thrombin potential, and mean velocity rate index) collected at baseline and six treatment cycles.

After six cycles of therapy, the ethinylestradiol-containing product arms displayed a mean thrombogram that was 97.5% over the median of all baseline thrombograms and outside the upper limit of the reference range. On the other hand, the mean estetrol/drospirenone thrombogram fell within the reference range. After six cycles of therapy, estetrol/drospirenone statistically had less impact on all thrombin production parameters than ethinylestradiol-containing products.

Compared to ethinylestradiol-containing products that, when combined with levonorgestrel or drospirenone, can increase the production of procoagulant factors and decrease that of anticoagulant ones, putting the patient in a prothrombotic state, an association of 15 mg estetrol with 3 mg drospirenone does not affect thrombin generation. Products containing ethinylestradiol thus produced prothrombotic conditions in contrast to estetrol, which had a neutral profile on hemostasis.