Anti-abortion activist Maribeth Kelly of Front Royal, Virginia, prays during a 2010 event in Washington.

Story highlights

41% of Americans say they're "pro-choice," the lowest number in Gallup poll history

Most polled say abortion should be legal only under certain circumstances

20% said it should be illegal in all cases; 25% said it should be legal in all circumstances

Advocates on both sides of the issue take heart in the findings

CNN  — 

The percentage of Americans who self-identify as favoring abortion rights has hit a record low of 41%, while those who consider themselves “pro-life” reached 50%, according to a new Gallup poll released Wednesday.

The prior record low for people who considered themselves “pro-choice” was 42% in 2009; that year 51% identified themselves as “pro-life,” according to Gallup.

First established in 1975, the survey asks if “abortion should be legal in all circumstances, legal only under certain circumstances, or illegal in all circumstances.”

Since 2001, the middle category has been chosen by about half of poll respondents, who far outnumber those who took either of the absolute choices. About 52% of those currently polled believe abortion should be legal under certain circumstances, a slight increase from last year’s findings of 50%.

About 20% want abortion to be made illegal in all cases, while about 25% want it legal in all cases, the poll found.

Anti-abortion groups were quick to hail the new findings.

“I think medical technology has a lot to do with it,” said Carol Tobias, president of National Right to Life, a Washington-based anti-abortion organization. “People are seeing ultrasound images of their unborn babies and it’s changing perceptions.”

But abortion rights groups downplayed the labels’ significance while also pointing to an apparently increased U.S. willingness to allow abortions in some circumstances.

“The survey shows Americans still strongly support keeping abortion safe and legal,” said Ted Miller, a spokesman for NARAL Pro-Choice America. “Pro-choice victories on ballot measures in states like Mississippi and South Dakota in the last few years, combined with the backlash against recent attacks on women’s reproductive rights, are a clear sign that voters want to protect a woman’s right to choose.”

CNN’s Chris Boyette contributed to this report.