A rare form of stroke called spontaneous subarachnoid hemorrhage (sSAH) is increasing among pregnant women, and African-Americans are particularly susceptible, according to research reported Jan. 24 at the International Stroke Conference in Los Angeles.

Spontaneous SAH occurs when the brain’s arteries weaken and cause ruptures in blood vessels on the surface of the brain, according to the American Stroke Association (ASA). The hemorrhages don’t cause head or neck trauma but lead to bleeding between membranes surrounding the brain.

Using a national database, researchers studied the cases of 3,978 pregnant women with sSAH from 2002 to 2014. They found the proportion of pregnant women admitted to the hospital for sSAH increased from 4 percent to 6 percent over the course of the study. In addition, sSAH affected 8 percent of pregnant black women, followed by 7 percent of Hispanics and 4 percent of whites.

“We need to increase awareness in the medical community about the increasing trend of spontaneous subarachnoid hemorrhage in pregnancy because management of these patients continues to be a clinical conundrum,” lead author Kaustubh Limaye, MD, an assistant professor in the division of cerebrovascular diseases at the University of Iowa, said in a press release.

Pregnant women with sSAH had favorable outcomes when compared to non-pregnant women hospitalized for sSAH. Eight percent of pregnant women with this form of stroke died compared to 17 percent of non-pregnant women, and pregnant women were more likely to be discharged home rather than to another medical facility.

Limaye said that contrasts with previous studies that showed poorer outcomes for pregnant women with sSAH.

Commenting on the study, Karen Furie, MD, pointed out pregnancy is “a high-risk period in general.”

“Women are at risk for subarachnoid hemorrhage, ischemic stroke, and intracerebral hemorrhage, and that's really related to all of the hemodynamic changes that occur during pregnancy and so just getting good prenatal care and monitoring blood pressure and other metabolic parameters is very important,” said Furie, the chief of neurology at Rhode Island Hospital, the Miriam Hospital and Bradley Hospital. “So overall, young people shouldn't be overly concerned. It's still a relatively rare cause of stroke.

“But lifestyle modification to even further diminish that risk is critical and it's important to also look into family history because aneurysms can sometimes run in families and so being aware that there might be first-degree relatives who suffer an aneurysm can help alert healthcare professionals that more either diagnostic imaging or intervention may be required.”

Furie said the study is a reminder for physicians to take it seriously when a pregnant patient complains of acute severe headaches because headaches and migraines share symptoms with sSAH.