Q&A with Barry Schwarz, M.D. - Birth Control and Stroke Risk

While stroke is the third leading cause of death for women in the U.S., few people know the risk of stroke associated with the use of birth control. The American Heart Association and the American Stroke Association recently published guidelines warning against the increased risk of stroke birth control may have on some women.

“The risk for heart attack and stroke is greatly increased if a woman takes birth control pills and smokes cigarettes, or takes birth control pills and has high blood pressure,” said Barry Schwarz, M.D., Professor and Vice Chair of Obstetrics and Gynecology at UT Southwestern Medical Center. He shares more information on what women should know before making a decision to begin birth control.

What is the most important thing for women to know about this topic?

It is important for women to understand that birth control pills do not inherently increase their risk for heart attack or stroke. However, cigarette smoking is known to increase the risk of heart attack, and high blood pressure increases the risk for stroke. In both cases, the risk is greatly increased if a woman takes birth control pills and smokes cigarettes or takes birth control pills and has high blood pressure. The vast majority of couples who do not want a pregnancy right now can find some method of contraception that will be both safe and effective.

Is birth control safe to use?

In May 1960, when oral contraceptives were first marketed in the United States, no one would have predicted how remarkably safe these hormones would be for millions of women taking them every day. Specifically, with regard to stroke, birth control pills alone do not increase the risk of stroke. However, high blood pressure does increase the risk of stroke, and the combination of birth control pills and high blood pressure is even riskier than high blood pressure alone.

What can women do to reduce their risk of developing high blood pressure?

A diet low in salt, sugar, and red meat, but high in vegetables, fruits, whole grain, legumes, poultry, fish, and nuts may be helpful. I also recommend regular exercise. Another tip, and perhaps the hardest, is to learn to relax – stress is also a contributing risk factor.

Can women with high blood pressure or high cholesterol take birth control?

Women whose high blood pressure is controlled with diet and exercise, or with medication, can take oral contraceptives. If a woman’s blood pressure becomes uncontrolled while taking birth control pills, she has to stop taking oral contraceptives. 

High cholesterol does not prevent women from taking birth control pills. However, a woman may very rarely have a dramatic increase in serum cholesterol and triglycerides if she takes birth control pills. If that happens, she must stop the pills. Incidentally, these rare individuals will have the same dramatic response in serum lipids when they become pregnant.

Describe the standard examination process for patients seeking to begin birth control.

Before prescribing birth control pills a health care provider should take or review a complete medical history and perform a physical exam appropriate for the patient’s age and symptoms. Height and weight should be measured, particularly if it is a first visit. A history of current cigarette smoking and the patient’s blood pressure will be of particular importance. If the patient has no symptoms and does not need screening for cervical cancer, a pelvic exam is not required for prescription of oral contraception.

Are there alternate birth control methods for women at risk for stroke?

While we would prefer to use non-hormonal contraception in women at risk for stroke, some hypertensive women, and women with multiple risk factors (obesity, diabetes, etc.) for cardiovascular disease, may be able to use hormonal contraception that does not contain estrogen in the form of pills, implants, or injections. Additionally, intrauterine contraception and barrier contraception (condoms, diaphragm, etc.) are safe options for the vast majority of women who are at high risk for stroke.

How often should women who take birth control and are also at risk for developing high pressure be evaluated by their physician?

A patient should have her blood pressure taken before starting birth control pills and again at three months later. Most patients who become hypertensive because of birth control pills do so within the first three months. After that, the patient’s blood pressure should be evaluated each time she refills her prescription and again when she obtains a new prescription for pills each year.