Medieval medical texts suggest different assessment of human fertility timeline

A new study analyzing medieval medical texts reveals that the perception of fertility declining with age differed significantly from modern understanding. 

In an article published by the University of Exeter, Professor Catherine Rider examined medical tests written between 1100 and 1300 to examine how fertility was perceived during that time period. The study, published in the Journal of Aging Studies, challenges modern assumptions about reproductive aging and highlights the historical perspective on fertility.

Medieval texts depict male and female reproductive aging as parallel processes that end suddenly rather than declining gradually. Instead of the modern concept of a biological clock and the decline of fertility over time, these texts portrayed reproductive aging as a variable process influenced by humoral balance. Medieval doctors perceived male and female reproductive aging in parallel with a woman's reproductive years clearly ending at menopause, while for men it ended at a lesser defined "old age." Since men were thought to remain fertile for significantly longer than women, "old age" for a man was defined as between 60 and 90 years; for a woman, "old age" was from 45 to 50 years. 

During her studies, Rider covered various notable texts including the encyclopaedia of Thomas of Cantimpré, a Dominican friar writing in the 1240s to the 1250s, the Pantegni and the Viaticum translated by Constantine the African, and the Book of the Conditions of Women, from the early twelfth century. The texts generally agreed that men were fertile until around the age of 70 or older and women were fertile until menopause which occurred around the age of 50. 

“The Pantegni, the Viaticum, the Book of the Conditions of Women, and many other medical texts into the seventeenth and eighteenth centuries stressed the importance of regular menstruation for fertility and included many remedies to bring on menstruation if it had ceased, as well as to reduce excessively heavy periods,” Professor Rider said, according to the press release. 

“Age was therefore presented as one among many factors that affected humoral balance and menstruation, and so fertility. They saw fertility as variable throughout the reproductive years, and potentially threatened by humoral or menstrual problems at any time, but only with the end of menstruation in women – or at a later age in men – did it definitively end.”