Consistent across cultures and throughout time is the male preference for younger females. Given its prevalence, the mate choice theory proposes that age-disparate relationships may have contributed to the evolution of maternal mortality and menopause. The objective is to document evidence for age disparity in marriage from past and present populations and evaluate their relevance to maternal mortality and menopause. Cross-sectional data were collected from various regions and time points, ranging from the Roman era to the current decade. To analyze both the age disparity in marriage and age at marriage, data were collected from Ancestry.ca for Quebec, Massachusetts, India, South Africa, and England and Wales. Additional data were taken from the United Nations as a more recent and comprehensive source. To analyze the relationships between age disparity in marriage and different social factors, data on gross domestic product, maternal mortality rates, fertility, primary school enrollment, child marriage rates, and percentage of women in the total labor force were collected from the World Health Organization, World Bank, and United Nations International Children's Emergency Fund. The results showed that males were significantly older than females at first marriage in all populations and time frames sampled, supporting the assumption underlying the mate choice theory. Maternal mortality rates were strongly associated with age-disparate relationships, increasing by 275 per 100,000 live births for each additional year in the age disparity. The results from this study provide support for the assumption underlying the mate choice theory of maternal mortality and menopause.