Rate of stroke increasing among women during, soon after pregnancy

Researchers gathered data from a large national database of 5 to 8 million discharges from 1,000 hospitals and compared the rates of strokes from 1994-95 to 2006-07 in women who were pregnant, delivering a baby and who had recently had a baby.

Pregnancy-related stroke hospitalizations increased 54 percent, from 4,085 in 1994-95 to 6,293 in 2006-07.

"I am surprised at the magnitude of the increase, which is substantial," said Elena V. Kuklina, M.D., Ph.D., lead author of the study and senior service fellow and epidemiologist at the Centers for Disease Control and Prevention's Division for Heart Disease and Stroke Prevention in Atlanta, Ga. "Our results indicate an urgent need to take a closer look.

Stroke is such a debilitating condition. We need to put more effort into prevention.

"When you're relatively healthy, your stroke risk is not that high," Kuklina said. "Now more and more women entering pregnancy already have some type of risk factor for stroke, such as obesity, chronic hypertension, diabetes or congenital heart disease. Since pregnancy by itself is a risk factor, if you have one of these other stroke risk factors, it doubles the risk."

For expectant mothers, the rate of stroke hospitalizations rose 47 percent. In pregnant women and in women who had a baby in the last 12 weeks (considered the postpartum period), the stroke rate rose 83 percent. However, the rate remained the same for stroke hospitalizations that occurred during the time immediately surrounding childbirth.

Pregnant and post partum women ages 25 to 34 were hospitalized for stroke more often than those who were younger or older.

Furthermore, high blood pressure was more prevalent in pregnant women who were hospitalized because of stroke.

In 1994-95, among pregnant women with stroke, researchers found high blood pressure in:

• 11.3 percent of the pregnant women prior to birth;
• 23.4 percent of those at or near delivery; and
• 27.8 percent of those within 12 weeks of delivery.

In 2006-07, they discovered high blood pressure among stroke patients in:

• 17 percent of those pregnant;
• 28.5 percent of those at or near delivery; and
• 40.9 percent of women in the postpartum period.

It's best for women to enter pregnancy with ideal cardiovascular health -- without additional risk factors, Kuklina said. Next, she suggests developing a comprehensive, multidisciplinary plan that gives doctors and patients guidelines for appropriate monitoring and care before, during and after childbirth.

A major problem is that pregnant women typically aren't included in clinical trials because most drugs pose potential harm to the fetus.

Therefore, doctors don't have enough guidance on which medications are best for pregnant women who have an increased risk for stroke.

"We need to do more research on pregnant women specifically," said Kuklina, who found only 11 cases of pregnancy-related stroke in her review of previously published literature.

Co-authors are: Xin Tong, M.P.H.; Pooja Bansil, M.P.H.; Mary G. George, M.D., M.S.P.H.; and William M. Callaghan, M.D., M.P.H. Author disclosures are on the manuscript.