Monday, October 26, 2009

Increased Stroke Risk from Birth Control Pills Detailed in Review Article

But Benefits Still Outweigh Risks for Most Users, Loyola Researchers Write

MAYWOOD, Il. -- She was only 30 years old, but she was experiencing the classic symptoms of a stroke. Her speech suddenly became slurred, and her left hand became clumsy while eating.

What triggered her stroke, at such a young age, may have been the birth control pills she was taking. Oral contraceptives nearly double the risk of stroke, according to a review article in MedLink Neurology by three Loyola University Health System neurologists.

Nearly 100 million women worldwide use birth control pills. Pills now in use contain much lower concentrations of estrogens than older preparations. The relationship between oral contraceptives and stroke has been studied and debated for decades, and studies have yielded conflicting results.

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 article. (The meta-analysis combined the results of multiple studies.) This is still a small risk; there's one additional stroke for every 25,000 women who take birth control pills, according to the article.

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.

"When prescribing oral contraceptives, doctors should balance the risks and benefits for each individual patient," said senior author Dr. Jose Biller. "For a healthy young woman without any other stroke risk factors, the benefits of birth control pills probably outweigh the risks. But if a woman has other stroke risk factors, she should be discouraged from using oral contraceptives."

The 30-year-old woman was one of two patients described in the article. She had suffered migraine headaches since she was 15 years old, which further increased her stroke risk. Doctors took her off birth control pills and gave her medication for her migraines.

Authors also described a 27-year-old woman who suffered severe right-sided headaches, nausea, vomiting and unsteadiness while on oral contraceptives. She stopped taking birth control pills and was treated with a blood thinner for six months. On a follow up visit, she was doing well except for occasional headaches.

"These observations obviously need to be considered in the proper context of a careful understanding of possible risks and benefits associated with the use of oral contraceptives, as well as those associated with other forms of contraception," Biller said.

How oral contraceptives might cause strokes is not completely understood. But two possible mechanisms are the increased risks of blood clots and high blood pressure associated with oral contraceptives, authors wrote.

Biller is chairman of the Department of Neurology at Loyola University Chicago Stritch School of Medicine. His co-authors are Dr. Michael J. Schneck, a professor in the Departments of Neurology and Neurological Surgery and lead author Dr. Sarkis Morales-Vidal, a stroke fellow in the Department of Neurology.

MedLink Neurology is the most up-to-date online resource for clinical neurologists. Loyola neurologists have written more than 10 articles for the journal.

About Loyola University Health System

Loyola University Health System (LUHS) is part of Trinity Health. Based in the western suburbs of Chicago, LUHS is a quaternary care system with a 61-acre main medical center campus, the 36-acre Gottlieb Memorial Hospital campus and more than 30 primary and specialty care facilities in Cook, Will and DuPage counties. Loyola University Medical Center’s campus is conveniently located in Maywood, 13 miles west of Chicago’s Loop and 8 miles east of Oak Brook, Ill. At the heart of the medical center campus is a 559-licensed-bed hospital that houses a Level 1 Trauma Center, a Burn Center and the Ronald McDonald® Children's Hospital of Loyola University Medical Center. Also on campus are the Cardinal Bernardin Cancer Center, Loyola Outpatient Center, Center for Heart & Vascular Medicine and Loyola Oral Health Center as well as Loyola University Chicago Stritch School of Medicine, Loyola University Chicago Marcella Niehoff School of Nursing and the Loyola Center for Fitness. Loyola's Gottlieb campus in Melrose Park includes the 255-licensed-bed community hospital, the Professional Office Building housing 150 private practice clinics, the Adult Day Care, the Gottlieb Center for Fitness, Loyola Center for Metabolic Surgery and Bariatric Care and the Loyola Cancer Care & Research at the Marjorie G. Weinberg Cancer Center at Melrose Park.

Trinity Health is a national Catholic health system with an enduring legacy and a steadfast mission to be a transforming and healing presence within the communities we serve. Trinity is committed to being a people-centered health care system that enables better health, better care and lower costs. Trinity Health has 88 hospitals and hundreds of continuing care facilities, home care agencies and outpatient centers in 21 states and 119,000 employees.