Effect of fertility and infertility on longevity

Changing demographic trends and projections of the survival and fertility rates of each generation have been a topic of great interest to not only demographers and epidemiologists but also to evolutionary biologists and reproductive endocrinologists. Compelling evolutionary theories suggest that there is an inverse association between fertility and longevity. Multiple historic, demographic, and current studies have since been conducted to test this theory, but the results have been inconclusive. The average number of children born to each woman has been declining progressively in developed countries during recent decades. This is in part due to changes in the behavior of couples but also to environmental factors. While improved accessibility to assisted reproductive technology can relieve some of the burden of infertility on these couples and lessen the problem of low total fertility rates in many developed countries, it is not enough to overcome the overall decrease in total fertility rates that we have witnessed in recent decades. This article critically reviews some important studies and provides an overview of this ongoing debate, while highlighting the relevance of trying to understand the possible mechanisms that may link fertility and infertility to longevity. (C) 2015 by American Society for Reproductive Medicine.