There is no widespread agreement on the number of rapes in the U.S. because of underreporting to police and because some rape counts include offenses that couldn't result in pregnancy, such as attempted but not completed rape, other sexual assaults, and rape of men, writes Carl Bialik in the Wall Street Journal. As for the likelihood that a rape could cause pregnancy, calculating that would require reliable figures on rates of ejaculation by rapists, on the exact ages of rape victims, and on the rate of their hormonal-contraceptive use, all of which are known with various degrees of uncertainty.
“The data suck,” said Prof. Jonathan Gottschall of Washington & Jefferson College in Washington, Pa., who says that contrary to a suggestion by Rep. Todd Akin, the Republican U.S. Senate candidate in Missouri, rapes are more likely than other sexual encounters to lead to pregnancy. “The data are not great. There are all kinds of caveats that need to be sprinkled around.” The Rape, Abuse & Incest National Network, an anti-sexual violence nonprofit group based in Washington, D.C., estimates that 3,204 pregnancies result from rape each year in the U.S. The Justice Department’s National Crime Victimization Survey “doesn't capture information on whether a pregnancy resulted from rape,” said Shannon Catalano of the Bureau of Justice Statistics.