A study finds that these rare hemorrhages are spontaneous. Learn the risk factors and signs to look out for. 

By Kristen Fischer
January 25, 2018
Rare stroke
Credit: Virojt Changyencham/Shutterstock

A newly released report found that spontaneous subarachnoid hemorrhage (sSAH)—a rare type of stroke—is increasing among young, pregnant women.

The stroke is a hemorrhage caused by a brain artery abnormality that causes blood vessels on the brain surface to deteriorate and break. This leads to bleeding between the membranes that surround the brain. The hemorrhage happens without a head or neck trauma.

Researchers looked at 3,978 pregnant women admitted to hospitals with sSAH between 2002 and 2014 and found that number of cases increased from 4% to 6% and that the largest group of women to suffer from these strokes were in their 20s.

What are signs of this stroke?

"Any sudden onset of vision loss, weakness, altered speech, or impaired gait/balance should raise the suspicion of stroke and prompt us to seek urgent medical attention," says Aravind Ganesh, M.D., a doctor with the Center for Prevention of Stroke and Dementia at the University of Oxford. This subtype of stroke is characterized by the sudden onset of a severe, or thunderclap, headache as well as losing consciousness.

Patients also might notice nausea, photophobia, neck stiffness, and some may develop neurologic deficits, added Elizabeth Klodas, a cardiologist from Minnesota.

"Rather than panic, the important thing that we would like pregnant women to know is that if they have atypical (different than usual) headache or [the] worst headache of their life they should seek immediate medical opinion," says Kaustubh Limaye, M.D., clinical assistant professor at the University of Iowa in Iowa City.

Who's at Risk?

Dr. Ganesh said women with aneurysms, high blood pressure and other vascular risk factors—including smoking—are at risk.

His 2014 research in Neurology uncovered that women with hypertension in pregnancy (especially severe forms like pre-eclampsia/eclampsia) are at a higher risk of strokes during and beyond pregnancy than other pregnant women.

Survivors of the stroke receive emergency care to fix their underlying blood vessel abnormalities. Long-term rehabilitation may be required as well. Dr. Klodas said survivors are monitored intensely and may need high blood pressure medication. Diuretics and other medications may also be necessary to reduce the pressure inside the skull, she added.

Dr. Klodas said pregnant women shouldn't panic about the report as strokes during pregnancy are still rare. While younger women of color had higher incident rates, it is unclear if they are statistically significant.

The study did not look at why rates are rising, but Dr. Klodas said the spike could be related to higher rates of obesity, hypertension, or obesity among the pregnant population. "You have to wonder if this is not somehow linked," she said.

Dr. Limaye believes one possible reason for the uptick in discovered cases could be increased access to better imaging. His team wants to continue studying the topic.