May 15, 2012 — As litigation swells against Bayer regarding the risk of blood clots tied to oral hormonal contraceptives, a new study has just been published linking non-oral hormonal contraceptives to an increased risk of blood clots as well.
These products include the patch (OrthoEvra), vaginal ring (NuvaRing), subcutaneous implants (Implanon, Nexplanon), and more. The study found no increased risk of blood clots associated with uterine implants (IUDs).
The study was conducted between 2001 and 2010. It involved approximately 1.6 million women from Denmark. The women were between 15-49 years old, were not pregnant, and had no medical history of blood clots or cancer. Exactly 5,287 women suffered their first-ever venous thrombolic event during the study, most often Deep Vein Thrombosis (DVT).
DVT is a severe medical condition that occurs when blood clots form when there is no injury, usually in veins deep within the lower leg, thigh, or pelvis. It is unlikely that the body will spontaneously dissolve the clot. DVT clots may grow to enormous size without treatment. They can severely damage veins, resulting in permanent circulation problems in the legs. DVT blood clots can also break loose, travel to the lungs, and cause a life-threatening pulmonary embolism.
The researchers found the following increased risks, which are compared to the baseline risk of blood clots in women who do not use hormonal contraceptives:
- Skin patch (OrthoEvra): 7.9-fold increased risk
- Subcutaneous contraceptive implant (Implanon, Nexplanon): 1.4-fold increased risk
- Vaginal ring contraceptive (NuvaRing): 6.5-fold increased risk
The researchers found that intrauterine devices (IUDs) were not associated with an increased risk of blood clots. The researchers did not analyze the risk with spermicidal sponges, such as TodaySponge.
Dr. Ojvind Lidegaard, the lead researcher who authored the study, had this to say about the increased risk:
“The transdermal patch and vaginal ring confer at least a sixfold increased risk of venous thrombosis as combined pills with desogestrel or drospirenone, a risk which is about twice the risk among women using second-generation pills with levonorgestrel.”
The researchers recommended that women who had already given birth might benefit by choosing an intrauterine device (IUD) that contains only progestin, because the contraceptive is not associated with an increased risk of blood clots, and it may actually protect against them. For women who have not given birth, the researchers suggested a birth control pill that contains levonorgestrel.