WASHINGTON — The number of abortions being performed in America has dropped to 1.2 million a year — the lowest level since 1976, according to a new report.

The drop was driven by a decline in the overall rate women of childbearing age are getting abortions, which fell about 9% between 2000 and 2005, according to a nationwide survey. At the same time, the long decline in the number of abortion providers appears to be stabilizing, at least in part because of the availability of the abortion pill RU 486, the report found.

The report did not identify reasons for the drop in abortions, but the researchers said it could be due to a combination of factors.

“It could be more women using contraception and not having as many unintended pregnancies. It could be more restrictions on abortions making it more difficult for women to obtain abortion services. It could be a combination of these and other dynamics,” said Rachel Jones of the Guttmacher Institute, a reproductive health research organization publishing the report in the March issue of the journal Perspectives on Sexual and Reproductive Health.

Whatever the reasons, the trend was welcomed by both anti-abortion and abortion rights advocates.

“This study shows that prevention works, and that’s what we provide in our health centers every day,” Cecile Richard of the Planned Parenthood Federation of America said. “At the end of the day, Americans of all stripes believe that we need to do more to prevent unintended pregnancy and make health care affordable and accessible.”