Risk of Pregnancy-Associated Stroke Across Age Groups

MedicalResearch.com Interview with:
Eliza Miller, M.D
Vascular Neurology Fellow
New York-Presbyterian Hospital/Columbia University Medical Center
We collaborated with researchers at the Massachusetts General Hospital and with the New York State Department of Health.

MedicalResearch.com: What is the background for this study? What are the main findings?

Response: Prior research has found that older women of childbearing age are at higher risk of stroke during pregnancy and postpartum than younger women. We hypothesized that their increased stroke risk might not be due to pregnancy-related factors, but just due to the fact that stroke risk increases with age for all people. We used billing data from New York State hospitals to calculate incidence risk ratios for four age groups: 12-24, 25-34, 35-44 and 45-55. In each age group, we compared the incidence of stroke in women who were pregnant or postpartum to the incidence of stroke in women of the same age who were not pregnant.

As in prior studies, we found that the incidence of pregnancy-associated stroke was higher in older women compared to younger women (about 47/100,000 deliveries in the oldest group, versus 14/100,000 deliveries in the youngest group). However, the incidence ratios showed that pregnancy increased stroke risk significantly in women under 35, but did not appear to increase stroke risk in women over 35. In the youngest group (age 12-24), pregnancy more than doubled the risk of stroke, and in the 25-34 age group, pregnancy increased stroke risk by 60%. In women aged 35 and older, pregnancy did not increase stroke risk. Women who had pregnancy-related strokes tended to have fewer traditional vascular risk factors like hypertension and diabetes, compared to same-aged women with non-pregnancy related strokes.

MedicalResearch.com: What should readers take away from your report?

Response: Our study suggests that while older women who get pregnant may be at higher risk of stroke than younger pregnant women, it may not be related to pregnancy; it may just be that the risk of all strokes increases with age. You can get a sense of this from the fact that about 1 in 5 strokes in women under the age of 35 in our study was related to pregnancy, whereas in the 35 and older crowd, it was more like 1 in 100.

MedicalResearch.com: What recommendations do you have for future research as a result of this study?

Response: My hunch is that the pathophysiology of pregnancy-associated stroke may be quite different than other kinds of strokes, and that there may be different risk factors we should be looking at. I think our understanding of why these pregnancy-associated strokes happen and how to prevent them is still very limited. That’s what my current and future research is focusing on.

MedicalResearch.com: Thank you for your contribution to the MedicalResearch.com community.


Risk of Pregnancy-Associated Stroke Across Age Groups in New York State
JAMA Neurol. Published online October 24, 2016. doi:10.1001/jamaneurol.2016.3774
Eliza C. Miller, MD1; Hajere J. Gatollari, MPH2; Gloria Too, MD3; et al

Note: Content is Not intended as medical advice. Please consult your health care provider regarding your specific medical condition and questions.

More Medical Research Interviews on MedicalResearch.com