Is there a link between pregnancy and stroke? Yes, says new study

A new study published in the Journal of the American Medical Association’s neurology site looked at the incidence of stroke by age and gender and how it might relate to pregnancy. It looked at patients in New York state who had certain stroke-related billing codes from 2003 to 2012. It divided the women into age groups as well as whether they were pregnant or within six weeks of having been pregnant.

The found a direct relation between pregnancy and stroke, which was even more pronounced the younger the women were. Women ages 12 to 24 had more than double the rate of stroke risk during or right after pregnancy. Those 25-34 had a 60 percent increase of stroke rate.  These are still relatively small numbers though: In the 12-24 group, it was 14 women per 100,000 versus 6.4 per 100,000 for nonpregnant/postpartum women. In the 25-34 age group, 21.2 per 100,000 pregnant or post pregnant women had stroke versus 13.5 per 100,000.

The risk is not significantly different after age 34. In the 35-44 group it was 33 per 100,000 versus 31 per 100,000. And in the 45-54 group, it’s 46.9 pregnant or post-pregnant women with strokes versus 73.7 nonpregnant women with strokes. The risk for stroke goes up with age,  but the pregnancy does not appear to affect it as much in that 35-44 age group. And the oldest group, probably doesn’t have as many pregnancies to begin with, thus limiting the number of stroke patients who have also been pregnant recently or are pregnant.

Dr. Steven Warach is the medical director of Seton's Stroke Institute.

Dr. Steven Warach is the medical director of Seton’s Stroke Institute.

What is significant about this study is that it does find the correlation between pregnancy and younger women who have had stroke. Dr. Steven Warach, who is the medical director of the Seton’s Stroke Institute, explains that the prevailing thinking is that there is a link between estrogen and blood clotting. We know that there is a link between stroke and oral contraception that contains estrogen and stroke and hormone replacement therapies with estrogen in them, he says. Pregnancy and those six weeks of post-pregnancy are a time when a woman’s estrogen levels are high and then in flux.

What the study also found was the type of stroke these women were having. The pregnant or post-pregnant women were having strokes from clots in their veins instead of in their arteries, which is the more common type of stroke.

Of the pregnant or postpartum women who had had strokes, 54.1 percent had had a cesarean delivery, 32.5 percent had had gestational hypertension, preeclampsia or eclampsia; 14.7 percent had had an infection present, about half of which was the bacterial infection chorioamnionitis.

Why weren’t the numbers higher for pregnant women versus nonpregnant women after age 35? More conventional risk factors such as high blood pressure, cholesterol and diabetes start to go up in the regular population. The pregnant women who had had strokes were less likely to have those risk factors, though.

Warach emphasizes that having a stroke during or after pregnancy is still a rare thing, as is strokes in younger women, but it can happen. He reminds of the importance of good prenatal care starting early in the pregnancy so that risk factors such as gestational diabetes and preeclampsia can be monitored. Pregnant or women who are post-pregnancy should be getting help immediately if they notice any change in neurological function or a severe headache. Time is of the essence with a stroke.

Remember the FAST acronym:

Face drooping to one side. Ask a person to smile.

Arm weakness. One arm is weaker than the other or is numb. Ask a person to raise both arms. Does one drift downward?

Speech difficulty. Is their speech slurred? Are they unable to speak? Can they repeat a sentence correctly and clearly.

Time to call 9-1-1. If they have any of these symptoms, even if they go away, call 9-1-1 and get them to the hospital.