The Utah House on Tuesday backed a bill that would ban elective abortions after 18 weeks gestation, a measure even supporters acknowledge will likely trigger a lawsuit if it passes.

All but a handful of the chamber’s Republicans backed the measure in the 57-15 decision, and nearly all Democrats opposed it. Members of the minority party contended it would flout established constitutional law, cost the state money to defend and interfere with decisions best left to a woman, her medical provider and her trusted counselors.

GOP lawmakers argued that the proposed 18-week ban reflects Utah values and medical advancements that have changed understanding of the procedure since the landmark Roe v. Wade decision.

“We now know much more than we did know about abortion in 1973 and its risks to women’s health,” the bill’s sponsor, Rep. Cheryl Acton, R-West Jordan, said on the House floor.

Rep. Keven Stratton, R-Orem, who supported the bill, marveled that well before the 18-week mark, it’s possible to “hear a heartbeat and to see the miracle of life springing forth.”

Rep. Brady Brammer, R-Pleasant Grove, said 18 weeks is longer than the National Football League season.

“You have an entire NFL football season to make this decision. That is no small amount of time,” he said.

Proponents of the 18-week ban listed a variety of drawbacks to allowing abortion later in a pregnancy, such as risk of physical and emotional damage to women and the possibility that the fetus would feel pain.

The point at which a fetus begins to experience pain has been the subject of scientific debate. But House Minority Leader Brian King said the state addressed this concern a couple years ago by enacting the nation’s first law requiring anesthesia for fetuses during elective abortions after 20 weeks (Acton later rebutted that this doesn’t seem to be happening in practice).

Existing state law prohibits abortions after a fetus could survive outside of the womb, and King said viability is a more appropriate and legally defensible cutoff point.

“That is much better than an arbitrary time limit for the simple reason that viability changes,” he said.

Federal courts have upheld the viability standard as constitutional, and most providers in Utah voluntarily stop offering the procedure at 21 weeks in order to avoid performing abortions after the state’s legal prohibition kicks in, Acton has said.

Her initial bill would’ve established a 15-week ban, but she upped that to 18 weeks after being advised it would make the legislation easier to defend in court.

Acton on Tuesday said she’s advancing the bill in part because she objects to late-term surgical abortions that “shock the conscience," giving such a vivid description of these procedures that Rep. Angela Romero at one point asked her to use less-graphic language.

Romero, of Salt Lake City, later explained that the no votes cast by her and her Democratic colleagues do not signify a disregard for human life but a desire to respect the choices of Utah women.

"We have no business making that decision for them," Romero said.

While the vote largely was divided along party lines, Democratic Rep. Sue Duckworth, of Magna, supported the bill and Republican Reps. Craig Hall of West Valley City and Steve Waldrip of Eden broke with their caucus to oppose it.

"I'm very pro-life. But I was concerned with the constitutionality of the bill," Hall wrote in a message following the vote. "The likelihood of success on a lawsuit appears low and if the state loses, the state will likely be forced to pay years of attorney fees to the opposing attorneys, out of taxpayer funds."

Waldrip in a previous committee hearing said he was unsettled by the “arbitrary" and “paternalistic nature” of the measure.

Acton has estimated the cost of defending the bill in court could total between $1 million and $3 million, if the state loses.

After her legislation, HB136, passed the chamber, Acton asked fellow lawmakers to add a statement on the bill’s background and purpose to the House Journal. She said she’d received legal advice that putting the intent language into the journal could help the state defend the 18-week ban if it’s contested in court.

Acton’s bill includes exceptions to the ban, including circumstances where a pregnancy is the result of rape or incest or threatens the life and health of a mother. She said the new version of her bill will also provide an exception in cases where the fetus develops a severe abnormality or debilitating brain malfunction.