Higher Number Of Childbirths Linked To Lower Stroke Risk In Women — Study

 

A new study suggests that women who have had more children may have a lower risk of stroke and certain types of brain injury later in life.

The research found that a greater number of live births was associated with a reduced risk of stroke and “covert brain infarcts”, silent brain injuries detectable through imaging.

The findings are considered important, particularly as women are known to experience strokes more frequently than men in some age groups.

The study, titled “Number of Live Births as a Protective Factor Against Clinical and Covert Brain Infarcts: The Framingham Heart Study,” was published in the April

edition of the Journal of the American Heart Association.

Researchers reported that women who had three or more live births showed a lower risk of stroke, as well as reduced likelihood of vascular brain injury, even after adjusting for major cardiovascular risk factors.

However, the study found no significant link between stroke risk and other reproductive factors, such as age at menopause, hormone therapy use, or levels of certain reproductive hormones.

 

Commenting on the findings, Sudha Seshadri, a behavioural neurologist and founding director of the Glenn Biggs Institute for Alzheimer’s and Neurodegenerative Diseases at UT Health San Antonio, noted that reproductive history may play a role in understanding stroke risk in women.

“Inclusion of this risk factor in female-specific clinical prediction rules for stroke may enhance risk prediction in women,” she said.

The researchers analysed data from the Framingham Heart Study, an ongoing community-based study that began in 1948 in Framingham, Massachusetts, United States.

The study followed 1,882 women who were stroke-free at the start of the research between 1998 and 2001, with an average age of 61. Participants were tracked over a median period of 18 years.

During that time, 126 women experienced strokes. Researchers also examined Magnetic Resonance Imaging scans to identify covert brain infarcts, which are small areas of brain damage that may not cause immediate symptoms.

Using statistical models that accounted for major vascular risk factors, the study found a consistent association between having three or more live births and a reduced risk of both stroke and vascular brain injury.

The researchers also examined other reproductive factors, including age at first menstruation, age at menopause, hormone replacement therapy, and levels of estrogen-related hormones such as estradiol and estrone, but found no clear association with stroke risk.

Experts note that reproductive factors influence a woman’s lifetime exposure to estrogen, which has been linked to brain and vascular health. Some studies suggest that longer or higher exposure to the body’s natural estrogen may be associated with a lower burden of small-vessel brain disease.

However, the relationship between childbirth and stroke risk remains complex, and previous research has produced mixed results.

The authors emphasise that while the findings highlight a potential link, they do not establish a direct cause-and-effect relationship.