Exercise helps lower stroke risk, but birth control pills and pregnancy can be problematic for younger women.
Women are at greater risk for strokes than men, and for the first time women and their doctors have evidence-based guidelines on how to reduce that risk.
"The take-home here is really about starting prevention earlier," says Dr. Cheryl Bushnell, an associate professor at Wake Forest Baptist Medical Center in Winston-Salem, N.C., and lead author of the guidelines published Thursday in Stroke, a journal of the American Heart Association.
"For the most part the focus of our guideline is for women who are thinking about getting pregnant," Bushnell tells Shots. That includes women who are trying to avoid getting pregnant by using birth control pills, and women who are trying to become pregnant.
That's years earlier than most women typically start thinking that they should worry about high blood pressure or stroke.
Women who are considering using birth control pills should get screened for high blood pressure, the guidelines say, because oral contraceptives increase the risk of blood clots and stroke.
And while these guidelines should be less controversial than recommendations published recently on high blood pressure for both men and women, they do suggest more aggressive use of medicines in pregnant women with high blood pressure.
"The only controversy for us is that we are recommending blood pressure treatment [with medication] during pregnancy," Bushnell says. "That's something the obstetricians may disagree with."
Blood pressure medications can restrict a fetus's growth. But high blood pressure in pregnancy can greatly increase a woman's risk of pre-eclampsia and stroke both while pregnant and for the rest of her life.
The new guidelines suggest considering blood pressure medication for pregnant women with blood pressure starting at 150 over 100. "It's not a rigid recommendation," Bushnell says. "The thought is if you don't wait until a woman's blood pressure is 160 over 110, which is dangerously high, and you have the ability to prevent that from happening, maybe that should be the focus in the future."
Pregnant women with severe high blood pressure, 160 over 100 or above, definitely should be given medication, the guidelines state.
Women who have a history of high blood pressure may need to take low-dose aspirin or calcium supplements while pregnant to reduce their risk of pre-eclampsia, a condition that can cause dangerously high blood pressure and stroke during pregnancy and that increases risk of high blood pressure afterward.
But women whose childbearing days are behind them aren't left out of the recommendations. Risk factors like high blood pressure, diabetes, migraine with aura, atrial fibrillation, depression and emotional stress tend to increase women's risk of stroke more than they do for men.
Each year, 55,000 more women die of stroke than men, according to the American Heart Association, and they die younger.
It used to be that women were thought to be at lower risk because they weren't as likely as men to carry excess belly fat. But now that women are getting fatter younger, those numbers have reversed. In 2008, 62 percent of women ages 20 and above had abdominal obesity, according to the national NHANES survey, compared with 44 percent of men.
Women's increased obesity may cancel out gains made in reducing stroke risk overall, the guidelines note. The guidelines list quitting smoking, regular exercise and healthful eating with programs such as the DASH diet as the best way to reduce risk overall.
Women over 75 should be screened for atrial fibrillation, an abnormal heart rhythm, the guidelines state. Atrial fibrillation increases the risk of stroke and can be treated with medication or surgery.