Hormonal birth control, such as the pill and implant, can increase a person’s risk for developing a blood clot. This is typically due to estrogen increasing the level of clotting factors in the blood.
A blood clot, also called deep vein thrombosis (DVT), is a type of clot in the venous blood vessels. It can break loose and travel to other areas of the body, such as the heart and lungs. In some cases, this can be life threatening.
Blood clots are dangerous, but they are also treatable.
It is important for people who use hormonal birth control to understand the risks involved. Although birth control increases the relative risk of blood clots, the absolute risk remains low.
Certain people may be more likely to get a blood clot, and they may want to use alternative contraception.
Nonhormonal birth control, such as condoms and the copper intrauterine device (IUD), could be a good option for people who want to reduce their blood clot risk.
Read more to learn about how birth control links to blood clots, the signs of a blood clot, and more.
- hormonal IUDs
- hormonal birth control pills
- hormonal implants
The absolute risk of blood clots is still low. The National Blood Clot Alliance reports that about 1 in 3,000 women taking birth control will get a blood clot in a year.
Although estrogen does not cause blood clots, it does increase blood’s ability to clot.
Some birth control only contains progestin.
Newer third- and fourth-generation birth control pills such as Mircette, Yaz, and Yasmine use these newer progestin hormones, drospirenone or desogestrel, combined with ethinyl estradiol. Research shows they may
In 2012, the Food and Drug Administration (FDA) issued an advisory suggesting that contraceptive pills containing drospirenone may increase the risk of blood clots up to
Any birth control containing hormones can increase a person’s risk for blood clots.
While estrogen is known to increase the blood clot risk, the role of progesterone in blood clots is less significant.
This suggests that it may be safer to take progesterone-only types of birth control.
It found that:
- progestin-only birth control pills did not significantly increase the risk of blood clots
- Mirena, a progestin-only IUD, did not significantly increase blood clot risk
- progestin injections, such as Depo-Provera, may increase blood clot risk
People with an increased risk for developing a blood clot, or who have had one before, should use a progestin-only option when choosing hormonal birth control.
- people with hypertension
- tobacco smokers over 35 years of age
- people with a history of venous thromboembolism (VTE)
- people with diabetes mellitus complications
- people with coronary artery disease
- people with migraine with an aura
Depending on the severity, it can either partially or fully block blood flow. If some of this blood clot breaks off and moves, such as to the heart or lungs, it can be very dangerous. A pulmonary embolism typically happens when a piece of DVT moves to the arteries that go to the lungs.
Although DVT is dangerous, it is also treatable when identified quickly. This is why it is important to know the signs of a DVT and be aware of the risk factors.
Birth control users are
- are 35 years of age or older
- do not move for a long period of time, such as on a long flight or after surgery
- have experienced an injury to the legs, such as a broken bone
- have other cardiovascular health risk factors such as high blood pressure, diabetes mellitus, or obesity
- have certain genetic risk factors, such as genetic blood clotting disorders
- have cancer, a serious infection, or an autoimmune disease such as lupus
Sometimes, a person may mistake a blood clot for a calf injury or bruise. People who have other risk factors such as the ones listed above should carefully monitor these injuries, as they may be something more serious.
If they get worse or do not go away, a blood clot may be the cause.
The most common symptoms of a blood clot in the leg
- pain in one leg, especially when walking
- swelling in just one leg or foot
- redness, warmth, and tenderness around a painful area in the leg
If the clot breaks loose and flows away from the site of the DVT, it can lead to chest pain, breathlessness, fainting, coughing, or very low blood pressure. If a person experiences these symptoms, they should
Estimates of the prevalence of blood clots caused by birth control vary. This is because, over time, studies have researched different types of birth control using different methods.
It is clear that the hormones in a particular contraception can play a role, as well as a person’s individual risk factors.
One 2015 study gathered data on combined birth control (containing both estrogen and progestin) users in the United Kingdom. Researchers found a rate of around
There is less research on progestin-only birth control. While it is generally considered a safer option for people with certain risk factors, it can
Third- and fourth-generation contraception
The risk of blood clots may be higher in people who use newer combined contraceptives containing desogestrel, gestodene, or drospirenone. Some of these birth control pills include Yaz, Yasmin, Safyral, Mircette, and Beyaz.
The American College of Obstetricians and Gynecologists (ACOG) committee echoes these concerns about some of the newer pills. But they also emphasize that some studies linking newer combined contraceptives to a higher risk of blood clots were somewhat flawed.
While the data on blood clots varies,
Some options for nonhormonal birth control
- Sterilization: This means a tubal ligation (“tying the tubes”) for females or a vasectomy for men.
- Condoms: These also protect against sexually transmitted infections.
- Diaphragms: These rest over the cervix. They contain spermicide to help prevent pregnancy.
- Nonhormonal intrauterine device (IUD): This type of IUD is a long-term birth control option, usually made of copper, which can last for years.
- Fertility awareness: This involves tracking one’s menstrual cycle to determine when a person is most fertile, then avoiding sex at those times.
Although some forms of contraception increase a person’s risk for developing a blood clot, the absolute risk is still low. For example, the risk is much higher during pregnancy. The Centers for Disease Control and Prevention (CDC) estimate that pregnancy increases the risk for blood clots about
Understanding a person’s individual risk factors, as well as knowing the warning signs of a blood clot, is important for people choosing to use hormonal contraception.
People who want to reduce their risk should consider either progestin-only or nonhormonal contraception.
Additionally, they should be mindful that some third- and fourth-generation pills such as Yaz have been linked to even higher blood clot risks.
A doctor can help a person choose the right birth control option for their individual needs.