June 3, 2013

“Normal” Women’s Reproductive Functioning: Myth Vs. Reality

Guest blogger Amy Harris presents the first in a series on what we know, and a few surprises about our assumptions, about the female body

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Stages in Female Evolution

Stages in Female Evolution

As a graduate student in biological anthropology who focuses on women’s reproductive health, I read a lot of interesting things about women’s bodies and how they function in various contexts. I’ve had the privilege of learning not just how the body functions from a traditional biomedical perspective (which tends to focus on women in industrialized populations), but also how much variation there is between women when it comes to things like hormone levels, menstrual schedules, experiences with contraceptive methods, and pre-menstrual syndrome. My training in graduate school has also taught me to consider how women themselves view their bodies and how they characterize their own experiences as biological and social individuals. As an anthropologist, I try not to judge women’s bodies or the decisions they make about their bodies, and I’m certainly in no position to make recommendations about how women should care for themselves! But I would like to share some insights that might help sort through the myths about sex hormones and reproductive functioning.

Dr. Virginia Vitzthum and I recently published an article  in which we tackled some of the myths surrounding women’s sexual and reproductive functioning. In this blog series I’ll be discussing a few choice topics from that article. In particular, I’ll be exploring some “myths” of women’s sexual and reproductive functioning that are commonly held by both professionals and nonprofessionals. By “myths” I don’t necessarily mean “lies,” but commonly-held misconceptions about women’s bodies that are not well substantiated by rigorous scientific studies.

Since I use an evolutionary framework to study these variations in women’s bodies, it might be helpful to go over a few fundamentals  on evolutionary theory: “Evolution” simply means change through time, and genetic evolution is made possible by mutation (changes in the genes), gene drift (when random events, like natural disasters, wipe out a significant portion of genetic variation by killing segments of the population), gene flow (when genes from one group of people are transferred to another group as people migrate and reproduce), and natural selection (some individuals are better able to reproduce than others, and, therefore, get more copies of their genes into future populations).

In this blog series, I’ll discuss how variation in women’s sexual and reproductive functioning might be adaptive, be the result of other adaptive processes, or simply just be. For our purposes, “Adaptation is the change by which organisms surmount the challenges to life” (Lasker, 1969).

We all vary from the “norm”

One of the broader themes I intend to develop here is that there is a no “universal” woman’s body—and that deviations from norms set by this idealized body not are “bad,” “unnatural,” or “unhealthy.” For example, as you’ll see in the next post, there is a great deal of variation in the duration and timing of a “normal” menstrual cycle. This is no trivial thing, as some women become concerned that their cycles are too long, too short, or too “irregular” and worry that they are unhealthy in some way. Relatedly, there is an idea floating around out there that there is some optimal level of reproductive hormones (estrogen and progesterone) that each woman “should” have—and “wrong” hormone levels have been blamed for everything from fertility problems to depression to problems with sexual functioning. While I’d never argue that hormones aren’t important for healthy functioning, what I hope to show is that there is no universal “set” level of hormones that a woman must have to be well. Anthropological research has shown that women across the world have drastically different reproductive hormone levels, yet are healthy (and fertile!). What these studies show is that, rather than worrying about what’s normal for some “ideal” woman’s body, what matters is what’s normal for a population, or even just for an individual operating in her own unique physical and social environments.

Here’s a snapshot of future posts:

1)    How much variation is there in the length and timing of a “normal” menstrual cycle? What does “normal” mean?
2)    What is PMS? Is it a “real” phenomenon? What do studies that try to document it in controlled settings find? How have researchers tried to explain it?
3)    Do women who spend time together cycle together? Is the evidence for menstrual synchrony as strong as many people assume?
4)    What the  “fertile window” is and why the “rhythm method” is seriously flawed as a form of family planning.

I look forward to exploring these issues in a way that will encourage us all to think broadly about what it means to be “normal,” and to think more critically about what we hear about women’s sexual and reproductive functioning!

Amy Harris is a PhD candidate in the IU anthropology department. She is currently developing her dissertation research on women’s experiences with oral contraceptives.