(CNN) - Rep. Todd Akin, who won Missouri's GOP Senate primary earlier this month and will face incumbent Democratic Sen. Claire McCaskill in November's general election, defended his hard-line stance against abortion in all cases this weekend by saying "legitimate rape" rarely resulted in pregnancy.
Answering a question about whether or not he thought abortion should be legal in the case of rape, Akin explained his opposition by citing unnamed medical mechanisms he said prevented pregnancy.
"First of all, from what I understand from doctors, that's really rare," Akin said of rape-induced pregnancy in an interview with KTVI. A clip of the interview was posted online by the liberal super PAC American Bridge.
"If it's a legitimate rape, the female body has ways to try to shut that whole thing down," Akin continued. He did not provide an explanation for what constituted "legitimate rape."
He added: "But let's assume that maybe that didn't work or something. You know I think there should be some punishment, but the punishment ought to be on the rapist and not attacking the child."
Statistics on pregnancies that result from rape are difficult to produce, since rape is a crime that often goes unreported. The Rape, Abuse & Incest National Network, along with Planned Parenthood, each estimate that 5% of all pregnancies occur after rape. A 1996 study from the Medical University of South Carolina found the same percentage, adding that 32,101 pregnancies occurred annually from rape.
Akin, a six-term U.S. congressman, touted his socially conservative values on the primary campaign trail, and gained the support of 2008 presidential candidate and former Arkansas Gov. Mike Huckabee. He was one of the first members of Congress to join the Tea Party Caucus in 2010 and has easily won re-election in recent years.
In his victory remarks, Akin thanked Huckabee, saying the former presidential candid date "stayed by our side, lifted us up in prayer, and tonight celebrates with us in victory." The lawmaker raised a notable $2.2 million this cycle, as of July 18.
McCaskill, who is up against Akin in November's general election, almost immediately struck upon her opponent's comments Sunday, writing on Twitter: "As a woman & former prosecutor who handled 100s of rape cases, I'm stunned by Rep Akin's comments about victims this AM."
McCaskill's website also splashed Akin's comments across the homepage, and included a link where supporters could donate money to McCaskill's campaign.