It has long been known that estrogen-containing birth control preparations (pill, patch, ring) increase the risk for DVT and PE (venous thromboembolism = VTE). This risk is partially due to the estrogen. However, part of the risk is also due to the type of progestin in these preparations. This first became clear when it was found that so-called 3rd generation contraceptives (containing the progestin desogestrel) have an about two times higher risk for VTE that the 2nd generation pills.
Drospirenone and Risk for VTE
In the last 4 years data have emerged that contraceptives containing the newer progestin drospirenone (such as Yasmin, Yaz, Angeliq) may also have a higher risk for VTE than the second generation pills. The FDA is presently reviewing the published data and expecting more data from clinical trials to form a solid opinion. Today the FDA published an update (link here) on “Safety review on the possible increased risk of blood clots with birth control pills containing drospirenone” – these pills are listed here. At this point the FDA concludes that (a) there are conflicting data on the risk for blood clots with these drospirenone-containing contraceptives, (b) preliminary results of an FDA-funded study suggest an approximately 1.5 fold higher risk of blood clots with these pills than with other contraceptive pills, and (c) that a drug safety meeting will take place at the FDA on Dec 8, 2011 to discuss the risks and benefits of these pills further.
When considering a contraceptive method, a physician and the woman should take all risk factors for VTE into consideration:
- Personal history of VTE
- Obesity (has emerged as a significant risk factor for OCP-associated VTE)
- Family history of VTE
- Presence of a thrombophilia
Taking into consideration the risk of VTE associated with each of the different type of methods, a decision of best contraceptive option can then be made. I have found it helpful in discussions to use the following graph (link here). In that image, the broad base of the triangle on top means “highest risk for VTE”, the green point at the bottom means “no risk for VTE”. A good choice for the thrombosis-prone individual is the Mirena IUD, which dos not seem to increase the risk for VTE. The Mirena IUD and other progestin-only contraceptives are discussed in a separate Clot Connect blog (link here).
Disclosure: I have no financial conflict of interest relevant to this post.
Last updated: Sept 26th, 2011
Disclaimer: ClotConnect.org, its contributors, authors, advisors, members and affiliate organizations do not assume any liability for the content of the website, blog and educational materials. Medical information changes rapidly. While information is believed to be correct, no representation is made and no responsibility is assumed for the accuracy.