Parity As a Protective Biomarker Against Silent Brain Infarction in Community-Dwelling Older Adults: The Sefuri Study

Background: Although several studies have reported an association between parity and increased risk of stroke, this relationship remains controversial. Aims: The present study aimed to determine whether parity is associated with silent brain infarction (SBI), independent of other confounders. Methods: We analyzed the brain magnetic resonance imaging findings in 576 of community-dwelling older adults with a mean age of 72.1 years. All female participants were asked to provide information regarding the total number of live births, their age at the last parity, and their age at menopause. Results: The prevalence of SBI and the number of infarcts per participant were higher in men than in women. Although all women who had given birth (0, 1-2, 3-4, or 5+ times) exhibited lower age-adjusted odds ratios (ORs) for SBI than men, a significant difference was observed between women with ≧5 births and men after adjustment for common vascular risk factors (OR:.348, 95% confidence interval [95% CI]:.123-.986). Among women who had given birth, the relationship between fertility and SBI was attenuated, but was enhanced after adjustment for age at the last parity (OR:.300, 95% CI:.102-.886). Conclusions: Our findings indicate that fertile women may be protected against SBI or cerebral small vessel disease via the biological effects associated with reproductive activity, and that high fertility may be a marker of protection against SBI. However, late childbearing may blunt protective effects of fertility against SBI.