Black Women Face Higher Stroke Risk After Hypertensive Disorders of Pregnancy

The risk for stroke is higher among Black women with a history of hypertensive disorders of pregnancy compared with the general population, according to study findings published in the Journal of American Heart Association.

Hypertensive disorders of pregnancy (HDOP), which includes gestational hypertension and preeclampsia, have recently been established as risk factors for stroke by the American Heart Association (AHA). Although Black women experience HDOP and stroke at higher rates than other racial groups, this correlation mostly originates from studies involving White women. For the study, researchers aimed to investigate the burden of HDOP and its association with stroke risk in a cohort of Black women.

The researchers gathered data from The Black Women’s Health Study (BWHS), a 25-year prospective cohort study of women across the United States dated from 1995. The analysis was conducted on women who had at least 1 birth (live or stillborn) with whom were free from any history of cardiovascular disease.

Biennial questionnaires documented self-reported gestational hypertension and/or preeclampsia/toxemia, as well as occurrences of physician-diagnosed stroke. Through the National Death Index (NDI), fatal strokes were obtained. For validity, self-reported stroke was assessed by a team of neurologists; stroke was defined by the World Health Organization (WHO): neurologic impairment lasting more than 24 hours (or leading to death) and of presumed vascular origin.

The primary outcome consisted of all self-reported first-onset strokes, as well as fatal strokes.

From a median follow-up time of 22 years, a total of 1555 incident stroke cases were identified from 42,924 women (median age, 38), that of which 310 cases occurred in 4,938 with a history of HDOP. When the researchers adjusted for age at first birth, body mass index (BMI) at age 18, educational attainment, and parental history of stroke, Black women were more likely to experience a stroke if they had a history of HDOP (hazard ratio [HR], 1.66; 95% CI, 1.46-4.89).

Compared with no HDOP, age-adjusted HR for stroke in those with HDOP was 1.72 (95% CI, 1.52-1.95). Comparable ratios were found to be 1.53 (95% CI, 1.29-1.82) for those with preeclampsia and 1.81 (95% CI, 1.53-2.13) for gestational hypertension without preeclampsia.

A secondary analysis conducted only on confirmed strokes (n=576) found the HR for stroke for any type of HDOP, compared with none was 1.73 (95% CI, 1.41-2.13), which translated to 1.63 (95% CI, 1.23-2.16) and 1.85 (95% CI, 1.41-2.43) for preeclampsia and gestational hypertension, respectively.

When stratified by age, the researchers found those aged younger than 55 were at a higher risk for stroke, when compared with those aged 55 and older (1.88; 95% CI, 1.55-2.26 vs 1.52; 95% CI, 1.28-1.80).

The nature of self-reported cases were cited as limitations, as there may have been misclassification, as well as underreporting of exposure in reference to cases of preeclampsia, gestational hypertension and stroke.

The researchers concluded, “Black women are disproportionately affected by both stroke and pregnancy complications. Cardiovascular screening recommendations for Black women in particular should take history of HDOP into account.”