A federal judge on Monday ruled against Tennessee for a second time this year, refusing to reinstate a 48-hour waiting period for abortions while the state appeals to a higher court.

In October, Judge Bernard Friedman ruled unconstitutional Tennessee's mandatory 48-hour waiting period for women seeking abortion, which had been in effect since 2015.

Though waiting periods have been struck down before in state courts, this case marks the first time a federal court has struck down an abortion waiting period.

In the legal challenge brought by Planned Parenthood and the pro-abortion Center for Reproductive Rights, Friedman wrote that most women are already certain about their decision to have an abortion when they go in for their first appointment.

The judge said the regulation placed an "undue burden" on women's "right to abortion."

Tennessee Attorney General Herbert Slatery filed a motion in November in the U.S. District Court in Nashville asking Friedman to keep the waiting period law in place while the state seeks the opinion of the 6th U.S. Circuit Court of Appeals.

On Dec. 14, Friedman refused, reiterating his opinion that "the Tennessee statute constitutes a 'substantial obstacle to a woman seeking an abortion' and, thus, an undue burden."

Tennessee Right to Life, a pro-life organization active in the state, decried the court's October decision, contending that the waiting period had saved "countless unborn lives" and spared women the regret of abortion by allowing them extra time to identify life-affirming resources near them.

"Not only is this decision a slap at Tennessee's abortion-vulnerable women, it is an affront to Tennessee's voters who passed a 2014 constitutional amendment in which allowing a short waiting period was a key factor," Brian Harris, president of Tennessee Right to Life, said at the time.

"Our organization remains committed to seeing a similar statute drafted and enforced during the next legislative session."

Tennessee's law required abortion doctors to inform a woman during her first appointment "that numerous public and private agencies and services are available to assist her during her pregnancy and after the birth of her child" if she chooses not to have the abortion.

Barring a medical emergency, a patient was then required to wait 48 hours before the second appointment and proceeding with the abortion.

Under Tennessee law, the district court's striking down of the 48-hour waiting period would automatically bring a 24-hour waiting period into effect for the state, but Friedman also blocked the state from enforcing the 24-hour requirement.

At least 26 states mandate waiting periods for women seeking abortions, most of them 24 hours. Five states- Utah, Missouri, Arkansas, Oklahoma, and South Dakota- have a 72-hour waiting period in place.

In Iowa, the legislature passed a 72-hour waiting period during May 2017, which the Iowa Supreme Court in 2018 declared unconstitutional. The Iowa House and Senate passed a 24-hour waiting period requirement for abortion during June 2020, which also requires a woman to have the chance to view an ultrasound of the unborn child and to receive information on adoption.

In January 2020, the authors of a study from Advancing New Standards in Reproductive Health (ANSIRH) reported that approximately 95% of women who had abortions did not regret their decision five years after the fact, even if they did initially experience regret. Friedman cited that study in his opinion.

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Dr. Priscilla Coleman, a professor of human development and family studies at Bowling Green State University who testified in the Tennessee case, told CNA that she disagrees with that study's conclusion and methodology.

In addition, larger studies have turned up opposite conclusions. While it did not directly measure "regret," a study by Dr. D. Paul Sullins of The Catholic University of America published in 2016 followed more than 8,000 women for over 13 years, and found that a significant increase in the relative risk of mental health disorders such as depression and anxiety for women who have abortions.