I read a really fascinating article in the most recent issue of Fertility and Sterility, which can be found here. The article, by Azziz, Dumesic, and Goodarzi, discusses the ancient existence of polycystic ovarian syndrome. The authors investigated how a disorder, which causes subfertility or infertility, could still persist at a relatively high level in modern times--theoretically, wouldn't it have been "bred out" of the species? It appears that increasing rates of obesity in Western cultures has not caused an increase in the rates of PCOS, so it is unlikely that change in diet has increased the prevalence of PCOS in moden times. The authors offered an intriguing explanation--that for much of human history, having PCOS has actually been advantageously adaptive, meaning that women with PCOS were more likely to survive and pass on their genetic material to the next generation.
It seems likely that PCOS actually had several adaptive advantages. In hunter-gatherer societies, food was often scarce. Women with PCOS, because of their insulin resistance, use food resources more efficiently. Their capacity to store food energy is greater, and they expend fewer calories, making them better able to survive times of starvation.
Further, because PCOS frequently causes subfertility rather than total infertility, women with PCOS had fewer children spaced farther apart in time. This was advantageous in a number of ways. With no or limited birth control, women often spent much of their life pregnant or giving birth. Even in the recent past, childbirth was extremely dangerous for women and was the top cause of female death. Thus, limiting the number of childbirths increased a women's likelihood of survival. In addition, by having fewer children, women with PCOS were more able to secure their children's survival--they more easily garner sufficient resources for them. Furthermore, children were more likely to survive if they were being raised by their biological mother, so the fact that women with PCOS had longer lifespans further enhanced their children's survival rates. In sum, it seems that for most of human history, having PCOS was actually a blessing, not a curse.
I think that looking at PCOS from the evolutionary perspective in this article has some valuable psychological implications. Most importantly, I think it is useful for anyone who is currently struggling with PCOS to realize that the disorder actually has some very important adaptive advantages. This will help them have more positive and less conflicted feelings about their bodies. Too often in infertility treatment, we end up feeling as if our bodies are vexing or failing us. Realizing that our bodies are actually trying to help us, although admittedly in a frustrating way, can be a reparative experience.
Looking at PCOS from an evolutionary perspective also made me wonder if there are other infertility diagnoses that have some of the same survival advantages. For example, could premature ovarian failure similarly enhance a woman's, and her offspring, chances of survival? When dealing with infertility, it is very easy to forget that for many men and women, both throughout history and in the present-day world, fertility has actually made their lives incredibly difficult. Perhaps the grass isn't always greener on the other side of the fence after all.