By Elise Viebeck - 02/03/14 11:22 AM EST
The U.S. abortion rate declined to its lowest point in 2011 since the procedure became legal across the country in the 1970s, according to research released late Sunday.
The Guttmacher Institute, a think tank that supports abortion rights, found in a census that the abortion rate dropped in 2011 to 16.9 abortions per 1,000 women of childbearing age.
The study also pointed out the 2011 rate is "well below" the 1981 peak of 29.3 abortions per 1,000 women.
The research was conducted via a census of abortion providers, and echoes previous findings by the Centers for Disease Control, which reported a decline in the abortion rate last year after surveying data from state health departments.
The new study coincides with persistent, heated debates over abortion rights in both Congress and statehouses across the country.
The fights are due in part to the wave election of 2010, which emboldened abortion opponents and ushered in a record number of restrictions on the procedure.
Republican legislators have vowed to redouble their efforts to limit abortions this year with statutes requiring waiting periods, ultrasounds and new standards for clinics.
Guttmacher attributed the falling abortion rate pre-2011 to improvements in contraceptive use, including a rise in long-acting methods like intrauterine devices.
They noted that the 2011 rate would likely not reflect the state laws passed the same year.
"The decline in abortions coincided with a steep national drop in overall pregnancy and birth rate," Rachel Jones, the study's lead author, said in a statement.
"Contraceptive use improved during this period … Moreover, the recent recession led many women and couples to want to avoid or delay pregnancy and childbearing."
Abortion opponents claimed victory in the numbers, arguing that the public is increasingly taking their side.
"The bottom line is that Americans and specifically women have become increasingly pro-life," said Concerned Women for America President Penny Nance in a statement.