Pregnancy complications linked to long-term stroke risk

Pregnancy complications linked to long-term stroke risk | Image Credit: © Chinnapong - © Chinnapong- stock.adobe.com.

The odds of future stroke are increased in women with complications during pregnancy, according to a study published in the European Heart Journal on June 24, 2025.¹

A common but overlooked risk factor

Over 2 million women were included in the analysis across a period of over 40 years. Those presenting with diabetes or high blood pressure during pregnancy, preterm delivery, or a baby with a low birth rate had higher rates of stroke in the following decades.

“Up to one-third of all pregnancies are affected by one of these complications. However, the long-term cardiovascular risks for these women remain poorly understood and so are often not considered in their routine clinical care,” said Casey Crump, MD, PhD, MS, MPH, professor at UTHealth.

The study was conducted to address these knowledge gaps.² Data was obtained from the Swedish Medical Birth Register, which includes nearly all Swedish deliveries since 1973. Since multiple gestation pregnancies have increased and differing causes of adverse outcomes, only singleton gestations were included in the analysis.

Key adverse pregnancy and stroke outcomes

Prenatal and birth records were assessed for 5 major adverse pregnancy outcomes, including preterm delivery, small for gestational age, preeclampsia, gestational diabetes, and other hypertensive disorders of pregnancy. Stroke incidence was assessed through December 31, 2018. Only stroke cases after 6 months postpartum were included.

The incidence of any stroke was reported as the primary outcome, while ischemic or hemorrhagic stroke was reported separately as secondary outcomes. Covariates included maternal age, parity, calendar year of delivery, education level at delivery, employment status, income, country of origin, body mass index (BMI), and smoking.

Prevalence of adverse outcomes

An adverse pregnancy outcome was reported in 667,774 women, comprising 30% of the cohort. In comparison, 8% of the cohort presented with at least 2 adverse pregnancy outcomes. Small for gestational age and preterm delivery were the most common adverse pregnancy outcomes, with rates of 14% and 9%, respectively.

A younger age at first delivery, reduced education level, and increased odds of smoking were reported in women with preterm or small for gestational age delivery. Additionally, those with preeclampsia had a lower education level and higher BMI, while those with gestational diabetes or other hypertensive disorders were older at first delivery.

Stroke incidence and follow-up

Stroke was reported in 1.6% of women over 48 million person-years of follow-up. Patients were aged a median of 27 years at first delivery, 55 years at stroke diagnosis, and 49 years at the end of follow-up. In women without death, the median follow-up duration was 27 years.

Variations in stroke incidence were observed based on adverse pregnancy outcome experience, with a 30-year incidence rate of 1.3% and a total cumulative incidence rate of 2.2% in women with preterm birth. In those with small for gestational age delivery, these rates were 1.3% and 2.2%, respectively.

Stroke Risk by pregnancy outcome type

Women with preeclampsia had rates of 1.8% and 3.1%, respectively, while those with other hypertensive disorders had rates of 1.5% and 1.8%, respectively, and those with gestational diabetes had rates of 1.3% and 1.9%, respectively. Overall rates in the cohort were 0.9% and 1.6%, respectively.

This indicated all links with stroke for all 5 adverse pregnancy outcomes. Hazards ratios for stroke were 1.86, 1.82, 1.40, 1.36, and 1.26 for gestational diabetes, other hypertensive disorders, preterm delivery, preeclampsia, and small for gestational age, respectively.

At 30 to 46 years, these HRs were 2.51, 1.60, 1.33, 1.23, and 1.23, respectively. These highlighted significant elevations remaining despite declines over time for 4 of the 5 outcomes, alongside an increase for gestational diabetes.

Clinical implications

This data highlighted increased risks of stroke in women experiencing a major adverse pregnancy outcome. Investigators concluded adverse pregnancy outcomes should be recognized as long-term independent risk factors of stroke.

“Both women and their doctors should now recognize that pregnancy complications are an early signal for future stroke risk. This can help us identify high-risk women long before they suffer a stroke or other cardiovascular disease,” said Crump.¹

References

1. Common pregnancy complications may be a signal of future stroke risk. European Society of Cardiology. June 23, 2025. Accessed July 8, 2025. https://www.eurekalert.org/news-releases/1087967.
2. Crump C, Sundquist J, Sundquist K. Adverse pregnancy outcomes and long-term risk of stroke: a Swedish nationwide co-sibling study. European Heart Journal. 2025. doi:10.1093/eurheartj/ehaf366