Risk of venous thrombosis in users of hormonal contraceptives in German gynaecological practices: a patient database analysis

Recent studies showed differences in the risk of venous thrombosis between different combined hormonal contraceptives. Database studies comprising large cohorts can add relevant aspects from daily clinical practice. The purpose of this study was to evaluate different progestogen in combination with ethinylestradiol on the risk of venous thrombosis in Germany. Computerized data from 68,168 contraceptive users in gynecological practices throughout Germany (Disease Analyzer Database) were analyzed. The adjusted odds ratios for risk of thrombosis were estimated in users of different oral contraceptive (OC) formulations relative to users of levonorgestrel-containing preparations. In total, 38 (0.06 %) of the 68,168 contraceptive users had a recorded diagnosis of thrombosis within 365 days after the initial prescription. The adjusted risk was 1.95 for desogestrel (95 % CI 0.52-7.29), 2.97 for dienogest (95 % CI 0.96-9.24), 1.57 for drospirenone (95 % CI 0.46-5.38), 2.54 for chlormadinone (95 % CI 0.72-9.04), and 3.24 for norgestimate (95 % CI 0.59-17.75) compared to levonorgestrel. None of those findings reached statistical significance. The maximum absolute increase versus levonorgestrel was 6 cases per 10,000 women (n.s.). The study shows the low incidence rates of thrombosis in OC users. Since there is no significant difference, this study does not confirm an increased risk but shows only a tendency for this risk of third- and fourth-generation OC versus levonorgestrel-containing products.