Previous parity differentially influences cognition in later life depending on dementia status.

Sex influences cognitive aging and dementia, yet research on the impact of female-specific factors, such as parity and fetal sex, on later-life cognition remains limited and equivocal. Inconsistencies in the literature may reflect varying effects across cognitive domains and dementia status. This study reviewed data from female participants of the University of British Columbia Hospital Clinic for Alzheimer and Related Dementias (UBCH CARD) to examine how parity and son-to-daughter ratio affect performance on medial temporal lobe-dependent (episodic memory) and prefrontal lobe-dependent (executive function) tasks depending on dementia status. Among females with dementia, higher parity was associated with reduced episodic memory but enhanced executive function performance, whereas a greater son-to-daughter ratio was associated with reduced executive function performance. These relationships were not observed in cognitively normal females or those diagnosed with mild cognitive impairment. These results emphasize the importance of integrating sex-specific factors into research and the development of precision therapeutics.