Todd Akin under pressure to quit as rape comments threaten GOP races
The row began when Akin, in an interview with the St Louis channel KTVI-TV broadcast on Sunday, was asked about his opposition to abortion, even in the case of rape.
"It seems to me, from what I understand from doctors, that's really rare," Akin replied. "If it's a legitimate rape, the female body has ways to try to shut that whole thing down. But let's assume that maybe that didn't work or something: I think there should be some punishment, but the punishment ought to be of the rapist, and not attacking the child."
Akin won the Republican primary only this month with the backing of Tea Party groups. The Missouri race, against Democratic Senator Clare McCaskill, was seen as one of the most winnable for the Republicans in its bid to take control of the Senate.
Akin is only narrowly ahead in the polls and pollsters predicted his remark is almost certain to lose him a lot of votes, especially among women.
But the row could also have implications for the White House campaign as it has focused attention on an area of sensitivity for Romney: the views on abortion of his running mate Paul Ryan.
In a statement released after Akin's remarks, Romney's campaign team said: "Governor Romney and Congressman Ryan disagree with Mr Akin's statement, and a Romney-Ryan administration would not oppose abortion in instances of rape."