WEDNESDAY, Oct. 26 (HealthDay News) -- Women who use oral contraceptives with desogestrel, gestodene, or drospirenone have an increased risk of first-ever venous thromboembolism (VTE), compared to users of oral contraceptives with levonorgestrel, according to a study published online Oct. 25 in BMJ.
Øjvind Lidegaard, Dr.Med.Sci., from the University of Copenhagen in Denmark, and colleagues evaluated the risk of venous thromboembolism from use of combined oral contraceptives according to the progestogen type and dose of estrogen. A cohort of 8,010,290 nonpregnant women, aged 15 to 49 years, from four registries in Denmark with no history of thrombotic disease were followed from 2001 through 2009. During this time, 4,307 first-ever VTE events were recorded, 4,246 were included, and 2,847 were confirmed as certain. The relative and absolute risks of first time VTE were assessed.
The investigators found that, for users of oral contraceptives, the relative risks of confirmed VTE were 2.9 with 30 to 40 µg ethinylestradiol with levonorgestrel, 6.6 with desogestrel, 6.2 with gestodene, and 6.4 with drospirenone, compared with nonusers of hormonal contraception. Using levonorgestrel as a reference and after adjusting for length of use, the rate ratios for VTE were 2.2, 2.1, and 2.1 for oral contraceptives with desogestrel, gestodene, and drospirenone, respectively. There was no increase in the risk of confirmed VTE with use of progestogen-only pills or hormone-releasing intrauterine devices.
"After adjustment for length of use, users of oral contraceptives with desogestrel, gestodene, or drospirenone were at least at twice the risk of venous thromboembolism compared with users of oral contraceptives with levonorgestrel," the authors write.
One of the study authors will be an expert witness for plaintiffs in a U.S. legal case, and disclosed financial ties with the pharmaceutical industry, including Bayer Pharma, which funded the study. Another author received compensation for work in the steering committee of the European Medicines Agency report.