The growth and development that people experience throughout their lifetime are accompanied by changes in their reproductive system. A person’s reproductive capacity differs between varying life stages. Ordinarily, sperm- and egg-producers become fertile and recognize themselves as reproductive beings during their adolescence or the years that follow puberty. As people continue to age and progress through their reproductive life cycle, natural age-related changes begin to affect everyone’s reproductive function.
Reproductive aging is a natural process that begins at birth and concludes with declines in reproductive function. Reproductive aging is typically characterized by gradual declines in fertility, fluctuations in the production of hormones, and declines in egg quantity and quality. Fertility is at its peak among egg producers 7 years after their first menstruation and regular cycles continue with age until they reach early their 40s. During this time, women in the US can spend close to thirty years trying to avoid an unintended pregnancy. As egg producers reach the end of their reproductive lifespans, menstrual cycles occur less frequently or cease entirely. Menopause is characterized by the cessation of menstrual periods for 12 months.
Reproductive aging affects sperm producers more gradually and results in a similar reduction in reproductive function. Reproductive aging among sperm producers is characterized by a slight decrease in testosterone production, lower levels of libido, and a reduction in spermatogenesis. Sperm produced by elderly bodies tends to have a different shape and decreased motility. However, sperm producers in their 70s are still capable of conceiving with younger partners.
Our colleagues at the Buck Institute are focused on understanding the mechanisms associated with reproductive senescence to develop strategies that inhibit ovarian aging. More specially, the Duncan Lab and Garrison Lab are working to improve reproductive lifespan by understanding the cellular, hormonal, and neurological processes that trigger reproductive aging. By doing so, researchers will be able to develop novel interventions that mitigate the health risks associated with reproductive aging and regulate age-related degenerative conditions.
Nuts & Bolts: Reproductive Aging