The exception comes just in time for the bill's Tuesday debate on the House floor.
Republican members of the House Judiciary committee voted down an amendment from Democratic leaders that would allow victims of rape to have an abortion after 22 weeks of pregnancy.
Rather than strike down the amendment entirely, GOP leaders instead suggested a different amendment.
The bill's sponsor, Rep. Trent Franks, argued against the exception last week, saying that the "incidents of rape resulting in pregnancy are very low."
Rep. Zoe Lofgren attacked Franks on his comments, and said to tell women they have to carry a pregnancy that is a product of rape is "outrageous."
Frank did not take back what he said, and said he was actually referring to the rarity of late-term abortions among raped women.
The measure is unlikely to succeed after the Democratic-led Senate attacked the original bill and the House Judiciary committee's lack of Republican women.
Rep. Marsha Blackburn, the bill's co-sponsor, will manage the debate rather than Franks in a push for more female GOP voices.