Study backs findings that some newer contraceptive pills more likely to cause VTE

A new study confirms earlier findings that certain oral contraceptive pills including those with desogestrel, gestodene, or drospirenone, including Safyral, from Bayer HealthCare, are more likely to cause serious blood clots (venous thromboembolism - VTE ) than others. The authors, led by Dr �jvind Lidegaard from the University of Copenhagen, say that women on pills containing one of the newer types of progestogen hormone (drospirenone, desogestrel or gestodene) have double the risk of VTE than women on pills containing an older progestogen (levonorgestrel). The researchers reviewed data of the hormonal contraception patterns and first time VTE episodes for all Danish non-pregnant women between the ages of 15 and 49 from January 2001 until December 2009. Though the relative risk of VTE whilst taking the oral contraceptive pill is still low, compared with non-users of hormonal contraception, pills with levonorgestrel increase the risk of VTE threefold and pills with drospirenone, desogestrel or gestodene increase the risk sixfold. In absolute terms, the risk of VTE in current users of newer pills is about 10 per 10,000 women years. See: "Risk of venous thromboembolism from use of oral contraceptives containing different progestogens and oestrogen doses: Danish cohort study, 2001-9" �jvind Lidegaard et al. British Medical Journal 2011;343:d6423 doi: 10.1136/bmj.d6423