The number of abortions performed in the United States has dropped to the lowest level in 40 years, a study said, pointing to more contraception use rather than increased restrictions on access to the procedure.
In 2011, an estimated 16.9 abortions were carried out per 1,000 women aged between 15 and 44 — 1.1 million in absolute terms.
It was lowest number since 1973, when the figure stood at 16.3 per 1,000, the Guttmacher Institute found.
Between 2008 and 2011, the abortion rate fell by 13 percent, as procedures were performed increasingly earlier in pregnancy.
The study, being issued Monday, noted that during that same period, the number of abortion providers fell by just 4 percent and clinics offering the service by just 1 percent.
The number of abortions reached a peak in 1981, with 29.3 terminations for every 1,000 women.
"With abortion rates falling in almost all states, our study did not find evidence that the national decline in abortions during this period was the result of new state abortion restrictions," said Rachel Jones, lead author of the study.
"We also found no evidence that the decline was linked to a drop in the number of abortion providers during this period."
Instead, the drop coincided with a steep dip in the numbers of overall pregnancy and birth rates.
"Contraceptive use improved during this period, as more women and couples were using highly effective long-acting reversible contraceptive methods," Jones said.
The devastating economic recession had also prompted many women and couples to delay pregnancy or childbearing.
Since early 2011, many states have implemented laws making it harder for women to seek abortion — with 205 new restrictions enacted between 2011 and 2013, more than the entire decade before.
"As we monitor trends in abortion going forward, it is critical that we also monitor whether these state restrictions are preventing women who need abortion services from accessing them," said Guttmacher Institute official Elizabeth Nash.
The study was based on analysis from a census of all known abortion providers in the United States and will appear in the March 2014 issue of the Guttmacher Institute's "Perspectives on Sexual and Reproductive Health."
Anti-abortion activists welcomed the reported dip in the numbers, insisting it validated their campaigning.
"That abortion rates and numbers continue to decline is heartening because it shows that women are rejecting the idea of abortion as the answer to an unexpected pregnancy," said Carol Tobias, president of the National Right to Life group.
"Overall, 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 mothers and their children are having a tremendous impact."