Maternal Age at Childbirth and Offspring Cognitive Function in Middle and Older Age: A Longitudinal Cohort Study

Current research on risk factors of dementia predominantly focuses on genetics and lifestyle, yet maternal influences are understudied; we aimed to examine how maternal age at childbirth affects offspring's cognitive function in middle and older age. Data were derived from 3549 offspring in the China Health and Retirement Longitudinal Study (CHARLS; 2011-2018). Maternal age was categorized into four groups (< 22, 22-28, 29-35, and > 35 years). Linear mixed‑effects models were used to estimate baseline differences and longitudinal rates of change, with covariates adjusted in a hierarchical sequence (demographic, socioeconomic, lifestyle, and health‑related). The negative association between advanced maternal age (> 35 years) and offspring baseline cognitive score attenuated with sequential covariate adjustment but remained significant: it was -0.290 SD (95% CI: -0.486, -0.093) in Model 1 and -0.223 SD (95% CI: -0.422, -0.024) in the final Model 4. No significant difference in the rate of cognitive decline was observed across maternal age groups. This finding suggests that advanced maternal age is associated with poorer cognitive performance at baseline in middle and older age. Future studies should replicate these findings in diverse global populations and settings with longer follow-up periods to clarify the complex relationship between maternal age at childbirth and offspring's cognitive aging. Patients or the public were not involved in the design, conduct, reporting, or dissemination plans of our research.