Science, rape, and pregnancy

Kate Clancy is one of my favorite bloggers. An anthropology professor at the University of Illinois, she studies the evolution of female reproductive anatomy. Her blog covers science I don't see anywhere else—the human evolution, cultural anthropology, and behavioral science behind ladybusiness.

So Clancy's blog was one of the first places I looked yesterday after reading about Missouri Rep. Todd Akin thoughtful commentary on female biology. In a long, well-written, and (fair warning) rather graphic post, Clancy talks about what we know about rape—think of it this way, you know way more people who have been raped than who have a gluten intolerance—and the way that emotional trauma affects conception and pregnancy.

First off, there is absolutely no difference in the rate of conception between women who have been raped and those who had consensual sex. Clancy breaks this down nicely in her blog post, and even offers a surprising tidbit from the research literature that all people should consider—at any given day in a woman's cycle (even days when she is supposedly "infertile") there's about a 3% chance of unprotected sex leading to a pregnancy.

The impact of stress on miscarriage is a lot messier. I've mentioned here before that we know very, very little about miscarriage, relative to a lot of other medical issues. To paraphrase my family practice doc, when you start talking about conception and miscarriage you very quickly wander past the small amount of hard evidence and straight into voodoo. And also into the counter-intuitive nature of reality. Read the rest