The amendment would allow for no exceptions for rape, The New York Times reported. The platform says unborn children have rights "that cannot be infringed."
"We support a human life amendment to the Constitution and endorse legislation to make clear that the Fourteenth Amendment's protections apply to unborn children," the approved draft said.
The full convention is scheduled to vote on the platform Monday.
The language comes at an embarrassing time for the party. Rep. Todd Akin, the Republican candidate for U.S. Senate in Missouri, refused to drop out after he said women who endured "legitimate" rapes were unlikely to become pregnant.
Republican National Committee Chairman Reince Priebus said on MSNBC that Mitt Romney, the almost certain presidential nominee, supports allowing exceptions to an abortion ban for rape and incest, The Hill reported.
"This is the platform of the Republican Party; it's not the platform of Mitt Romney," Priebus said. "That all being said, though, these guys are proud pro-life candidates and we're a proud pro-life party."
The platform contained the same language in 2004 and 2008.