Towards an understanding of women’s brain aging: the immunology of pregnancy and menopause

•Women are at higher risk for autoimmune conditions and Alzheimer’s disease.•Estrogen regulates immune function and neuroplasticity.•Pregnancy and menopause involve considerable changes in estrogen and immune function.•Previous pregnancies may influence menopausal inflammation processes.•Pregnancies may affect brain aging by fostering ‘optimal’ lifetime estrogen exposure. Women are at significantly greater risk of developing Alzheimer’s disease and show higher prevalence of autoimmune conditions relative to men. Women’s brain health is historically understudied, and little is therefore known about the mechanisms underlying epidemiological sex differences in neurodegenerative diseases, and how female-specific factors may influence women’s brain health across the lifespan. In this review, we summarize recent studies on the immunology of pregnancy and menopause, emphasizing that these major immunoendocrine transition phases may play a critical part in women’s brain aging trajectories.