Birth Control Pills Pose Risk of Stroke | News | Loyola Medicine
Monday, September 21, 2015

Loyola report finds that birth control pills pose small but significant stroke risk

MAYWOOD, Ill.  –  Birth control pills cause a small but significant increase in the risk of the most common type of stroke, according to a comprehensive report in the journal MedLink Neurology.

For healthy young women without any stroke risk factors, the risk of stroke associated with oral contraceptives is small. But in women with other stroke risk factors, “the risk seems higher and, in most cases, oral contraceptive use should be discouraged,” report co-authors Marisa McGinley, DO; Sarkis Morales-Vidal, MD; and José Biller, MD of Loyola University Medical Center and Loyola University Chicago Stritch School of Medicine.

Worldwide, more than 100 million women currently use oral contraceptives or have used them in the past. In the United States, there are about 40 brands of oral contraceptives and 21 brands of emergency contraceptive pills.

Strokes associated with oral contraceptives were first reported in 1962. Early versions of the pill contained doses of synthetic estrogen as high as 150 micrograms. Most birth control pills now contain as little as 20 to 35 micrograms. None contain more than 50 micrograms of synthetic estrogen.

Oral contraceptives increase the risk of ischemic strokes, which are caused by blood clots and account for about 85 percent of all strokes. In the general population, oral contraceptives do not appear to increase the risk of hemorrhagic strokes, which are caused by bleeding in the brain.

There are about 4.4 ischemic strokes for every 100,000 women of childbearing age. Birth control pills increase the risk 1.9 times, to 8.5 strokes per 100,000 women, according to a well-performed “meta-analysis” cited in the report. (A meta-analysis combines the results of multiple studies.) This is still a small risk; 24,000 women would have to take birth control pills to cause one additional stroke, according to the report.

But for women who take birth control pills and also smoke, have high blood pressure or have a history of migraine headaches, the stroke risk is significantly higher. Such women should be discouraged from using oral contraceptives, the report said.

Hormone replacement therapy with estrogen alone or combined with progesterone increases the risk of ischemic stroke by 40 percent; the higher the dose, the higher the risk, the report said.

The report is titled “Hormonal Contraception and Stroke.” It is an update of a report originally published in Medlink Neurology in 2003.

Dr. McGinley is a resident, Dr. Morales is an assistant professor and Dr. Biller is a professor and chair of the Department of Neurology of Loyola University Chicago Stritch School of Medicine.

About Loyola Medicine and Trinity Health

Loyola Medicine, a member of Trinity Health, is a quaternary care system based in the western suburbs of Chicago that includes Loyola University Medical Center (LUMC), Gottlieb Memorial Hospital, MacNeal Hospital and convenient locations offering primary and specialty care services from 1,877 physicians throughout Cook, Will and DuPage counties. LUMC is a 547-licensed-bed hospital in Maywood that includes the William G. and Mary A. Ryan Center for Heart & Vascular Medicine, the Cardinal Bernardin Cancer Center, a Level 1 trauma center, Illinois's largest burn center, a certified comprehensive stroke center and a children’s hospital. Having delivered compassionate care for over 50 years, Loyola also trains the next generation of caregivers through its teaching affiliation with Loyola University Chicago’s Stritch School of Medicine and Marcella Niehoff School of Nursing. Gottlieb is a 247-licensed-bed community hospital in Melrose Park with 150 physician offices, an adult day care program, the Gottlieb Center for Fitness, the Loyola Center for Metabolic Surgery and Bariatric Care and the Loyola Cancer Care & Research at the Marjorie G. Weinberg Cancer Center at Melrose Park. MacNeal Hospital is a 374-bed teaching hospital in Berwyn with advanced inpatient and outpatient medical, surgical and psychiatric services, advanced diagnostics and treatments. MacNeal has a 12-bed acute rehabilitation unit, a 25-bed inpatient skilled nursing facility, and a 68-bed behavioral health program and community clinics. MacNeal has provided quality, patient-centered care to the near west suburbs since 1919.

Trinity Health is one of the largest multi-institutional Catholic healthcare systems in the nation, serving diverse communities that include more than 30 million people across 22 states. Trinity Health includes 94 hospitals, as well as 109 continuing care locations that include PACE programs, senior living facilities and home care and hospice services. Its continuing care programs provide nearly 2.5 million visits annually. Based in Livonia, Mich., and with annual operating revenues of $18.3 billion and assets of $26.2 billion, the organization returns $1.1 billion to its communities annually in the form of charity care and other community benefit programs. Trinity employs about 133,000 colleagues, including 7,800 employed physicians and clinicians. Committed to those who are poor and underserved in its communities, Trinity is known for its focus on the country's aging population. As a single, unified ministry, the organization is the innovator of Senior Emergency Departments, the largest not-for-profit provider of home health care services—ranked by number of visits—in the nation, as well as the nation’s leading provider of PACE (Program of All Inclusive Care for the Elderly) based on the number of available programs.