"There's ample evidence that abortion doctors on any number of occasions have deceived women into thinking that they're pregnant, and then collect money for a procedure that they don't perform," campaign spokesman Rick Tyler told BuzzFeed. "And I say they don't perform it because obviously the women weren't pregnant."
The campaign of the six-term St. Louis-area congressman challenging Democrat Claire McCaskill for her U.S. Senate seat cited a Nov. 12, 1978, Chicago Sun-Times report as evidence doctors trick women into thinking they're pregnant to collect abortion-procedure fees.
The campaign also released a statement from anti-abortion activist Abby Johnson, who the campaign identified as a 2007-2009 director of a Planned Parenthood clinic in Texas.
"I can attest that when I served as director of Planned Parenthood in Bryan, Texas, we often scared women into getting services they did not need -- including abortion -- so we could collect the fees," her statement said. "This included women who were not pregnant and women who were in the process of miscarrying."
Akin told a St. Louis TV station Aug. 19 women who are raped had a natural ability to avoid pregnancy if the rape is "legitimate."
McCaskill said then it was "beyond comprehension that someone can be so ignorant about the emotional and physical trauma brought on by rape."
Her campaign declined to comment on Akin's 2008 remarks or his campaign's defense of them.
Two polls released Wednesday -- by Rasmussen Reports and Public Policy Polling -- showed Akin trailing McCaskill by 6 percentage points.
The Rasmussen poll has a 4.5 percentage point margin of error and the PPP poll has a 3.7 point error margin.
Shortly before he made his "legitimate rape" remark, Akin led McCaskill by 11 points in one poll and by 1 point in another.
Slate magazine published a video clip of an Akin House floor speech made Jan. 22, 2008, in which he linked abortion providers to terrorists.
He was one of several anti-abortion lawmakers who spoke on the House floor on the 35th anniversary of the 1973 Roe vs. Wade Supreme Court ruling that gave women a legal right to an abortion.
"We have terrorists in our own culture called abortionists," Akin said then.
He called doctors offering abortions "the very bottom of the food chain of the medical profession."
"And what sort of places do these bottom-of-the-food-chain doctors work in? Places that are really a pit. You find that along with a culture of death go all kinds of other lawbreaking -- not following good sanitary procedure, giving abortions to women who are not actually pregnant, cheating on taxes -- all these kinds of things -- misuse of anesthetics so that people die or almost die," he said in the speech. "All of these things are common practice."
Obstetrician Nancy Stanwood, a Physicians for Reproductive Choice and Health board member, said Akin's assertions then and now were unfounded and offensive to doctors.
"I think this reflects the fact that [Akin] is not an authority on women's reproductive health in the modern era," Stanwood told The Huffington Post. "What he's saying is baseless and medically ridiculous."
She said doctors performing abortions are "thoughtful and passionate."