Abortion rates in Wisconsin and across the country are the lowest they have been since 1973 – the year the gavel came down in the landmark Roe vs. Wade decision.

At both the state and federal level, both sides of the abortion debate have welcomed the news as progress for women and children, but pro-choice and pro-life groups disagree on the factors contributing to the decrease.

The report released by pro-choice think tank the Guttmacher Institute, surveyed abortion numbers in all 50 states and found the number of abortions dropped by 13 percent between 2008 and 2011.

In 2011, there were just under 8,000 abortions in Wisconsin, according to the report, a 6 percent reduction since 2008. Currently, there are four abortion clinics in Wisconsin.

Despite the drop in abortion rates since the national peak in 1980, there are still 1.1 million abortions every year across the country. According to the report, despite the decline, abortions are still a fairly common occurrence in the U.S. One in three American women will have an abortion by the time they reach 45, the report found.

Jenny Higgins, University of Wisconsin professor of gender and women’s studies, said despite this overall downward trend, abortion rates among poor American women have actually risen.

An article in the New Yorker said although the overall abortion rate fell by 8 percent between 2000 and 2008, the rate among poor women increased by 18 percent.

“I think we will very likely see a continuing disparity between wealthier women and non-wealthy women—the poor and the non-poor—as well as a disproportionate representation of women of color,” Carole Joffe, a sociologist at the University of California, San Francisco, said in the New Yorker.

Pro-life group National Right to Life, released a statement in which President Carol Tobias said the new numbers were “heartening,” as they show women are rejecting the idea that having an abortion is the answer to an unexpected pregnancy.

“This latest report from Guttmacher shows the long-term efforts of the right-to-life movement to educate the country about the humanity of the unborn child and to enact laws that help children and their mothers are having a tremendous impact,” Tobias said.

Rachel Jones, the main author of the report, said they found no evidence the reductions were linked to new state restrictions on abortion or decreases in the numbers of abortion providers.

In the report, Jones said a steep drop in overall pregnancy rates, in addition to increased use of long-term contraceptive methods such as the IUD, could offer some insight into the drop in abortion rates.

“Moreover, the recent recession led many women and couples to want to avoid or delay pregnancy and childbearing,” Jones said.

Higgins echoed these possible causes, adding the decline in pregnancy rates coincides with changing norms in family size within the U.S.

Rep. Melissa Sargent, D-Madison, also responded to the report, saying, “I think we can prevent abortions if we provide people with access to access to comprehensive sex education and contraceptives.”

Although fewer pregnancies are ending in abortion, Tobias said Guttmacher still reports that more than one in five pregnancies end in abortion.

“The right-to-life movement must continue its efforts to protect these children and their mothers from the tragedy of abortion and our society must do a better job in providing life-affirming alternatives,” Tobias said.