Rate of stroke three times higher among pregnant women

According to a new Canadian study, the rate of stroke is three times higher among pregnant women than non-pregnant women of the same age, an alarming finding that researchers say isn’t completely understood.

The study, published Friday in the International Journal of Stroke, analyzed numerous international studies from the last 27 years that addressed stroke incidence during pregnancy.

Researchers found that about 30 out of every 100,000 women will experience a stroke at some point during pregnancy. The likelihood of suffering a stroke is highest in the period immediately before and after birth, and the incidence of stroke is three times higher among pregnant women than non-pregnant women.

Study co-author and stroke neurologist Dr. Rick Swartz said many expecting moms are unaware of the increased risk.

“Stroke is a leading cause of death and disability in adults and when stroke occurs as a complication of pregnancy, the impact on the mother, child and families can be devastating,” Swartz, the director of the stroke research unit at Sunnybrook Health Sciences Centre, said in a statement.

The precise reason behind the increased risk requires more study, but researchers say their early findings may offer some clues. Hormonal changes in pregnancy and a condition known as pre-eclampsia – an abrupt and potentially deadly spike in high blood pressure – could partially explain the finding, researchers said.

The global meta-analysis found that geography may play a factor, too. Researchers found that some countries that offered universal pre-natal care reported lower rates of stroke in pregnant women. However, researchers cautiously describe the relationship as a “potential trend.”

How to limit risk

While pregnant women may be at an increased risk of stroke, that risk is still considered low, according to study co-author Dr. Patrice Lindsay.

“While all pregnancy-related stroke risk cannot be eliminated, there are things women can do to decrease their risk, including following a healthy diet, being physically active and smoke-free, managing blood pressure and stress and limiting alcohol consumption,” said Lindsay, the director of stroke for the Heart & Stroke Foundation of Canada, in a statement.

Experts advise that regular check-ups with a doctor during pregnancy can be an effective way to monitor the risk factors of stroke, such as pre-eclampsia, blood pressure and blood sugar.

The report says further research is “urgently needed” to analyze geographic differences in stroke rates among pregnant women and to improve the quality of available data.

An estimated 62,000 strokes occur in Canada per year, or about one stroke every nine minutes. About 80 per cent of people survive stroke, and more than 400,000 Canadians live with long-term disability from stroke.

The research was based in Canada and included authors from Sunnybrook, Western University, Harvard University, Wake Forest Baptist Health, workHORSE Consulting Group and Heart & Stoke.

The report was funded by Heart & Stroke, Canadian Institutes of Health Research, Heart & Stroke Foundation Canadian Partnership for Stroke Recovery, Sunnybrook Department of Medicine and the University of Toronto Department of Medicine.

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