A Utah bill requiring doctors to administer anesthesia to a fetus at 20 weeks’ gestation or later during an abortion procedure now heads to the governor’s desk, after Republicans on Thursday pushed through the measure during the legislative session’s final hours.

The bill, sponsored by state Sen. Curt Bramble (R-Provo), hinges on the unsubstantiated notion that a fetus at 20 weeks’ gestation feels pain, despite an exhaustive scientific review saying that’s simply not the case.

SB 234 passed in the house in a 56-13 party line vote, after clearing the state senate this month over Democratic opposition. Republicans control both chambers of the Utah legislature.

The legislation includes language saying “substantial medical evidence from studies” concludes that a fetus that is “at least 20 weeks gestational age may be capable of experience pain during an abortion procedure,” despite evidence to the contrary.

The Republican bill offers a few exceptions to the anesthesia mandate, such as cases in which the abortion is needed to save the patient’s life, preserve the pregnant person’s health, or if there’s a severe fetal defect. A physician may elect to forgo the fetal anesthesia by stating, in writing, that administering anesthesia to the fetus would put the patient’s life at risk or kill them.

Before a floor debate on the measure Thursday afternoon, floor sponsor Rep. Keven J. Stratton (R-Orem) said the legislation would provide “comfort” to the fetus during what he called a “gruesome and painful” procedure.

House Minority Leader Brian S. King (D-Salt Lake City) said he was “troubled” by politics coming between a pregnant person and a doctor.

“A fetus is not a child, it’s a potential child; an embryo is not a child, a zygote is not a child,” King told legislators. “None of those things are babies. I hear in our debates on abortion all the time references to killing babies … but babies do not exist in the womb, they exist outside the womb. Let’s honor the personal dignity of the women of Utah and vote this bill down.”

Third-trimester abortion care is rare, with 1.2 percent of terminations occurring at 21 weeks or later, according to the Guttmacher Institute. A 2010 report by the London-based Royal College of Obstetricians and Gynaecologists’ Working Party found no research to support the notion that a fetus feels pain prior to 24 weeks’ gestation, and did not recommend anesthesia before that gestational date.

“Because neural connections are not completely formed or fully active, most experts believe that fetuses at less than 24 weeks don’t have the capacity to feel pain,” Eleanor Drey, professor of obstetrics, gynecology, and reproductive sciences at the University of California, San Francisco, told Rewire. “And so providing anesthesia for something that probably doesn’t exist … would involve unnecessary risks to pregnant women.”

Late Thursday, the legislation bounced between the house and the state senate, passing in both chambers along party lines to accommodate last-minute amendments. Representatives passed it on a 57-10 margin, and it cleared the state senate, 25 to 3.

The bill now heads to the governor’s desk.

Utah Gov. Gary Herbert (R) previously told reporters he’d back the legislation, saying, “Rather than get into the abortion debate, I guess the question is: If we’re going to have abortion, what is the most humane way to do it?”

Montana Republicans last year passed similar legislation, which the state’s Democratic governor vetoed. The bill banned abortions performed at 20 weeks or beyond without anesthesia.

Separately, a Republican-led effort to ban providing abortion care via increasingly popular video-conferencing technology stalled this legislative session.

A few states administer medication abortion with telemedicine—where the doctor and patient connect via a secure video-conferencing system—but Utah isn’t one of them. HB 340 preemptively sought to bar practitioners from issuing “a prescription through electronic prescribing for a drug or treatment to cause an abortion, except in cases of rape, incest, or if the life of the mother would be endangered without an abortion.”