NASHVILLE (AP) — A federal appeals court on Wednesday once again reinstated a Tennessee ban on abortions because of a prenatal diagnosis of Down syndrome, or because of the race or gender of the fetus.

The ban is part of a sweeping anti-abortion measure that has faced multiple legal challenges since it was enacted in 2020 by Republican Gov. Bill Lee. Notably, the law banned abortion as early as six weeks — a time frame when most women don't know they're pregnant — but that portion has remained blocked from going into effect.

In Wednesday's decision, the 6th U.S. Circuit Court of Appeals granted the request by the Tennessee attorney general's office to reverse course and temporarily allow the so-called reason ban to be enforced. The 6th Circuit had blocked that provision in September after previously allowing it to go into effect in 2020.

The back-and-forth over the reason ban comes after the same federal appeals court signaled in December that it might be willing to allow Tennessee's fetal heartbeat measure to be implemented. The court vacated a previous decision made by the appeals court's three-judge panel and scheduled a rehearing before the full court.

In a four-page dissent, Circuit Judge Karen Nelson Moore wrote that the appeals court was refusing to schedule the hearing until the U.S. Supreme Court handed down its decision on whether to uphold Mississippi's ban on abortions after 15 weeks of pregnancy. The decision could dramatically limit abortion rights in the United States. According to Moore, the appeals court is waiting to see if the high court's decision will affect Tennessee's case.

"(These) stay-and-delay tactics subvert the normal judicial process, harming both the substance of our ultimate decision and our court's legitimacy," she added.

Attorneys representing the plaintiffs, which include reproductive rights advocates and health clinics that provide abortions, criticized Wednesday's ruling.

"Pregnant people are the ones best suited to make decisions about their own pregnancies, and politicians should not get to interrogate a person's reasons for seeking an abortion," Rabia Muqaddam, staff attorney at the Center for Reproductive Rights, said in a statement. "These bans are blatantly unconstitutional."

A spokesperson for the attorney general's office did not immediately return a request for comment.

The plaintiffs also have argued the ban was improperly vague, claiming the law failed to provide clear guidelines for abortion providers to avoid criminal prosecution.

Currently, more than a dozen states have similar reason bans in place. However, even Tennessee's state attorneys have acknowledged that it would be incredibly difficult for a prosecutor to prove that a physician knew in advance that a woman was seeking an abortion because of a Down syndrome diagnosis. The law calls for criminal penalties against doctors who violate it.

Down syndrome is a genetic abnormality that causes developmental delays and medical conditions such as heart defects and respiratory and hearing problems.

According to the National Down Syndrome Society, about one in every 700 babies in the United States — or about 6,000 a year — is born with the condition, which results from a chromosomal irregularity. There are no official figures on how many prenatal diagnoses of Down syndrome prompt a decision to abort; a 2012 study by medical experts estimated the abortion rate was 67%.