As abortion continues to define the Republican presidential primary, Mitt Romney's campaign said Wednesday that Romney's wife, Ann, made a $150 contribution to Planned Parenthood in 1994, the year Romney ran for Senate as a candidate supporting abortion rights.

Romney spokesman Kevin Madden said Ann Romney does not remember whether it was a straight donation to the abortion rights group, which supports abortion rights, or whether she wrote the check as an admission fee for an event.

"Since it was so long ago, Ann has no information of the circumstances," he said.

Madden confirmed the payment in response to a question from the Globe.

He said the check was written from the Romneys' joint checking account, but she signed it and the contribution came from her, Madden said. Mitt Romney has not donated to the organization, Madden said.

A spokesman for the Planned Parenthood League of Massachusetts, Angus McQuilken, declined to comment. "It is our policy not to comment on contributions," he said.

The disclosure of Ann Romney's contribution comes as one of Romney's leading GOP rivals, former New York mayor Rudy Giuliani, is taking heat from conservatives for having made at least six donations to Planned Parenthood chapters with his wife at the time, Donna Hanover, in the 1990s. Giuliani has often said that although he favors abortion rights, he personally "hates" and "abhors" abortion and would counsel a pregnant woman against it. Giuliani's contributions were first reported by The Politico, a new political news organization.

Giuliani and Romney are facing questions about their records on abortion as they try to win Republican primary voters,

who have generally backed candidates opposing abortion.

Romney favored abortion rights when he ran for Senate and then for governor of Massachusetts in 2002, but he has shifted to an antiabortion position in recent years and now calls himself "firmly pro-life."

Thursday, Romney is scheduled to address a Mother's Day dinner in Agawam sponsored by the Massachusetts Citizens for Life, a group with whom he has a rocky history. The organization criticized Romney while he was governor but became more supportive as Romney shifted to an antiabortion position. Romney recently made a $15,000 contribution to the group.

Giuliani still favors abortion rights, though he, too, has taken more conservative positions on the issue during the presidential campaign, and he has struggled to answer questions about his position. He was roundly criticized after saying in last week's inaugural Republican debate in California that "it would be OK" if the Supreme Court overturned its 1973 Roe v. Wade decision, but also "OK" if it didn't.

A spokesman for the other leading Republican presidential candidate, Arizona Senator John McCain, said neither McCain nor his wife had ever given to abortion rights groups.

Ann Romney's position on abortion also appears to have shifted. In a TV interview from the 2002 gubernatorial campaign, clips of which have been posted on YouTube, Ann Romney says that women voters "may be more nervous" about her husband on social issues. "They shouldn't be, because he's going to be just fine," she said. "But the perception is that he won't be. It's an incorrect perception."

Mitt Romney adds, "So when asked will I preserve and protect a woman's right to choose, I make an unequivocal answer: yes."

But Ann Romney is now cochairwoman of Massachusetts Citizens for Life's capital campaign. And in an interview earlier this year with ABC News, she said she agreed with her husband's opposition on abortion.

Scott Helman can be reached at shelman(AT)