A study published in May, 2009 by the British Medical Journal notes that women using hormonal contraceptives containing drospirenone, such as Yaz®, are about 64% more likely to develop blood clots than the average woman using hormonal contraceptives. Blood clots pose a very serious risk to health, as they may cause heart attack or stroke.
For the study, titled “Hormonal contraception and risk of venous thromboembolism: national follow-up study” by Lidegaard et al. surveyed the health of 10.4 million women, and found that in the general population, the risk for developing blood clots was about 3 out of every 10,000 women, while the risk for women using hormonal contraceptives was about double that, at 6.29 out of 10,000 women. But the Lidegaard team did not stop their research at that discovery; the study went on to evaluate the relative risk of developing blood clots for different kinds of hormonal contraceptives.
Compared to the average risk of developing blood clots posed by the ingestion of hormonal contraceptives, the study found that medications containing desogrestrel place women about 82% more likely to develop blood clots than the average user of hormonal contraceptives, gestodene about 86% more likely, cyproterone about 88% more likely, and drospirenone about 64% more likely than the average hormonal contraceptive user to develop blood clots.
However, concerning what was considered the “crude rate” of blood clot development, calculated simply by dividing the number of blood clots observed by the number of woman-years for each particular pharmaceutical discussed in the study, drospirenone (YAZ®) was found to be the most dangerous, averaging 7.8 observed blood clots per 10,000 users. This stood above all other hormonal contraceptives tested, with norethisterone at 4.5, levonorgestrel at 5.8, norgestimate at 4.6, desogestrel at 6.5, gestodene at 7.0, and cyproterone at 7.1 observed blood clots per 10,000 women.
Because of the startling information presented here, this article can be used in a Yaz lawsuit, demonstrating that the risks of YAZ® are much higher than the average hormonal contraceptive.