Concerns about birth control’s effects on heart health are common. This article explores the relationship between different types of contraception and the cardiovascular system, providing information on how these methods might influence heart health and what factors can affect individual risk.
Hormonal Birth Control and Cardiovascular Health
Hormonal birth control methods, which use synthetic estrogen and/or progestin, are the primary focus regarding cardiovascular health. Combined oral contraceptives (COCs) contain both hormones, while mini-pills, implants, injections, and hormonal intrauterine devices (IUDs) are progestin-only. These hormones affect the cardiovascular system. Estrogen, in particular, can alter blood clotting factors, increasing the blood’s tendency to clot.
Hormonal contraceptives can also impact lipid profiles, potentially raising levels of triglycerides and “bad” LDL cholesterol while sometimes lowering “good” HDL cholesterol. They may also influence glucose tolerance and activate the renin-angiotensin-aldosterone system, which plays a role in blood pressure regulation.
Progestin-only methods generally present a lower cardiovascular risk profile compared to COCs. For instance, a progestin-only IUD has not been linked to an increased risk of heart attack or stroke, making it a safer option for some individuals.
The risk associated with combined hormonal methods can vary depending on the delivery method and specific progestin used. Non-oral combined contraceptives, such as the vaginal ring and skin patch, have shown higher risks for stroke and heart attack compared to combined oral pills. The birth control patch, for example, delivers more estrogen than low-dose pills, which may contribute to a higher risk of blood clots. Some progestins, like drospirenone and desogestrel, have also been associated with a greater risk of blood clots than other progestin types.
Understanding Specific Cardiovascular Risks
Hormonal birth control use has been associated with specific cardiovascular conditions, though the absolute risk for healthy individuals remains low. One concern is venous thromboembolism (VTE), which includes deep vein thrombosis (DVT) in the legs and pulmonary embolism (PE) in the lungs. Estrogen in combined hormonal contraceptives increases the risk of VTE by altering coagulation factors in the blood. The overall risk of developing a blood clot is small, estimated at 3 to 9 per 10,000 women using birth control pills annually, compared to 1 to 5 per 10,000 non-users.
Some hormonal contraceptives can lead to an increase in blood pressure, known as hypertension. This effect is linked to the estrogen component in combined oral contraceptives, with higher estrogen doses contributing to a greater risk. About 5% of COC users may experience an increase in blood pressure, which is reversible within three months of discontinuing the medication. Regular blood pressure monitoring is important for individuals using these methods.
An associated risk of stroke, particularly ischemic stroke, exists with hormonal birth control. Combined oral contraceptives have been linked to approximately a twofold increased risk of ischemic stroke. The vaginal ring and skin patch demonstrate even higher associated risks, with the vaginal ring increasing ischemic stroke risk by 2.4 times and the patch by 3.4 times. Despite these increases in relative risk, the absolute risk of stroke remains low, translating to about one additional stroke for every 4,760 women using the combined pill for one year.
Heart attack (myocardial infarction) is another rare cardiovascular event linked to hormonal birth control. Combined oral contraceptives are associated with about a twofold increased risk of heart attack. The vaginal ring can increase heart attack risk by 3.8 times, while the patch also carries an elevated risk. For most women under 35 without other risk factors, the absolute risk of heart attack remains very small. The risk of blood clots is higher during pregnancy and the postpartum period than with hormonal contraceptive use.
Factors Influencing Individual Risk
Several pre-existing conditions and lifestyle factors can amplify an individual’s susceptibility to cardiovascular problems when using hormonal birth control. Age plays a role, with women over 35, especially those who smoke, facing a higher risk for serious cardiovascular events. Smoking alone can increase the risk of myocardial infarction tenfold and stroke nearly threefold in COC users. Obesity also contributes to an elevated cardiovascular risk profile.
Pre-existing health conditions, such as high blood pressure, diabetes, and high cholesterol, directly multiply the risks associated with hormonal contraceptives. A personal or family history of blood clots, stroke, or heart attack also indicates a higher individual predisposition. Certain genetic predispositions, including the Factor V Leiden mutation or other hereditary thrombophilias, can increase the likelihood of blood clots. Women with a high genetic predisposition for blood clots are six times more likely to develop a clot during the first two years of using contraceptive pills compared to those with a low genetic risk.
Migraines with aura are an important consideration, as taking combined oral contraceptives can heighten stroke risk for individuals experiencing them. Women younger than 45 with migraine with aura already face a higher baseline risk for ischemic stroke. A thorough evaluation of an individual’s health profile is important before prescribing hormonal contraception.
Informed Decision-Making for Contraception
Making an informed decision about contraception involves a comprehensive discussion with a healthcare provider. Disclose a complete personal and family medical history, particularly concerning cardiovascular health, blood clots, and migraines. This allows the healthcare provider to assess individual risk factors and recommend the most suitable contraceptive method based on a personalized risk-benefit assessment. Regular medical check-ups and blood pressure monitoring are important while on hormonal birth control, as blood pressure can increase in some users.
For individuals with certain cardiovascular risk factors, alternative contraceptive methods may be more appropriate. Non-hormonal options, such as copper IUDs, do not affect cardiovascular risk directly and can be suitable choices. Progestin-only methods, including mini-pills, implants, and hormonal IUDs, are safer alternatives for those with higher cardiovascular risk, as they do not increase blood pressure or the risk of blood clots to the same extent as combined methods. Users should also be aware of potential symptoms of serious cardiovascular events, such as sudden leg pain or swelling (DVT), chest pain or shortness of breath (PE), sudden weakness or vision changes (stroke), or chest pain radiating to the arm or jaw (heart attack), and seek immediate medical attention if these occur.