Infamously, Missouri's Republican Senate nominee Todd Akin said on Sunday that doctors had told him that pregnancy from rape was really rare. "If it's a legitimate rape," Akin said, "the female body has ways to try to shut that whole thing down."
Akin has already felt the political repercussions from the debacle. Two prominent funders, including Karl Rove's Super PAC American Crossroads, have withdrawn their funding for his campaign. Top Republicans have called for his resignation from the campaign. Akin who, was leading in the polls against Democratic rival Claire McCaskill by eight percentage points on Sunday, now leads by one point, a statistically insignificant margin.
But what about the veracity of his comments? Are they rooted in facts, even a little bit? Well, no. One 1996 study about the incidences of rape-related pregnancy found that 5 percent of rapes resulted in pregnancy. One study put that number as high as 8 percent in cases in which birth control was used. For comparison, in consensual, unprotected sex, the pregnancy rate is only 3.1 percent.
Last year, the Centers for Disease Control and Prevention reported that 1 in 5 women have been raped during their lifetimes; 1.3 million women aged 18 or over had been raped in 2011. Popular Science reports that, statistically, over 83,000 women would have become pregnant at the hands of a rapist in 2011 alone.
So why does rape seem to be a more effective strategy for procreation? Scientists have many theories. One is that rapists tend to target women who are young and pretty who, by all measures, are at their peak fertility. Indeed, most victims of rape are young women under the age of 25; pre-pubescent, post-menopausal, and visibly pregnant women are underrepresented in the statistics.
Another theory is that the semen of rapists has something to do with their reproductive success. One of the hormones in semen is the follicle stimulating hormone (FSH), which has been shown to trigger ovulation in various animals. One study in 1973 found that 70 percent of conceptions from rape occurred outside of women's most fertile time in their menstrual cycles. One study, taken in 1949, cited seven women who reported becoming pregnant as a result of rape, even though they had not menstruated in up to two years.
In addition, the circumstance in which semen is produced seems to have some effect on fertility as well. Semen's quality changes depending on whether a man was aroused by his imagination, watching porn, or having pulled out. Gordon Gallup, an evolutionary psychologist at the State University of New York at Albany, in an interview with Popular Science, from an evolutionary standpoint, that changing the chemical makeup of semen would be an effective strategy to make sure that your genes are passed during rape (as sinister as that is).
While it doubtful that Akin's quote was about this, there is also a theory that preeclampsia, or hypertension during pregnancy, arose to keep a woman's body from accepting foreign sperm. Researchers have noted that it is more common during pregnancies conceived from one-night stands and artificial insemination. Incidences of the condition are even more common in cases of couples that had been using condoms or the withdrawal methods before attempting to conceive.
However, the statistics of pregnancies from rapes speak for themselves, despite the origins of preeclampsia. It is clear that the number of pregnancies from rape are, indeed, statistically significant.