The rate of abortion, in decline for nearly three decades, stalled in 2008, according to the Guttmacher Institute, a research organization that tracks abortion trends.
The rate was 19.6 abortions per 1,000 women in 2008. That's down from 29.3 abortions per 1,000 women in 1981.
"In this time of heightened politicization around abortion, our stalled progress should be an urgent message to policymakers that we need to do more to increase access to contraceptive services to prevent unintended pregnancy, while ensuring access to abortion services for the many women who still need them," said Sharon Camp, president and chief executive of Guttmacher, in a statement.
More women were also choosing a two-drug combination for a "medication abortion," verses a surgical one, the group found. The number of such procedures was 199,000 in 2008, up from 161,000 in 2005. And as a percentage of nonhospital abortions, the early medication procedures rose to 17 percent from 14 percent.
Nearly 60 percent of abortion providers offer the drugs.
The group also found that the number of abortion providers was about the same in 2008, rising to 1,793 from 1,787. About 87 percent of U.S. counties – where about 35 percent of women in their reproductive years live -- had no one providing abortions.
Those nonhospital abortion providers reported an increase in "harassment," which is defined by the group as picketing and blocking patient access.
The data was collected in the group's 15th "census" or abortion providers. It's published online in the Perspectives on Sexual and Reproductive Health.
Officials at Planned Parenthood Federation of America, which supports abortion rights, said the study "highlights the need for our leaders to ensure that all women and their partners have the information and affordable birth control options they need to prevent unintended pregnancy. The first step we can take as a nation is to increase access to affordable contraception. While many factors contribute to the abortion rate in the United States, this country's very high rate of unintended pregnancy is the most important one of all."
The group has launched a campaign called Birth Control Matters to advocate for prescription birth control without co-pays through the new health care law.
The National Right to Life Committee, which opposes abortion, said legislative and educational efforts have helped prevent an increase in abortions.
But, "with abortion continuing to claim the lives of more than 100,000 unborn children every month, we must continue to be vigilant in our efforts to educate the public and enact laws that protect unborn children and their mothers from the dangers of abortion and make sure they know that help is available," said Randall K. O'Bannon, the group's director of education and research, in a statement.