PIERRE, S.D. (AP) — Lawmakers in South Dakota are considering whether to ban doctors from performing gender-affirming operations and treatment on minors.

A bill introduced Tuesday in the Republican-dominated Legislature would make it a felony for medical providers to perform operations or administer hormone therapy to help minors affirm their gender. The proposed law would not apply to children born with ambiguous or conflicting genitalia.

Rep. Fred Deutsch, a Florence Republican, introduced the bill in the House on the first day of the legislative session with more than 40 co-sponsors. He called the proposed law a “pause button” for minors who want to get a gender-affirming operation.

“The changes are overwhelming and life-changing. Children need to wait until they’re mature to do it,” Deutsch said.

The lawmaker called gender-affirming operations and hormone therapy “dangerous” because of the psychological and physical toll it takes on minors. He said the bill would not interfere with children’s ability to “socially transition,” in which a person may take on the dress, name or behavior of their gender.

The American Civil Liberties Union said the bill targets transgender youth who are already vulnerable.

“(Transgender) kids and families should be given the opportunity to thrive in South Dakota,” Libby Skarin, policy director for the ACLU of South, said in a statement. “This legislation only stands to harm them and make their lives harder.”

Democratic legislative leaders said they would oppose the bill.

Rep. Kelly Sullivan, a Sioux Falls Democrat, said the measure would interfere in the doctor-patient relationship, and that doctors, patients and families should make decisions for treatment.

Sullivan said she is not aware of medical centers that provide gender-affirming treatments for minors in the state and called the bill a waste of time by Republicans.

Deutsch said he has found several instances of doctors administering gender-affirming treatment in Sioux Falls.

Conservative lawmakers in several states including Texas, Georgia and Kentucky have introduced similar bills. Deutsch said he decided to introduce the bill after reading about the issue online. He also consulted with a group called Kelsey Coalition that opposes gender-affirming operations for minors.

The Endocrine Society, which is the leading professional organization for doctors who specialize in hormones, does not recommend gender-affirming medical treatment before puberty for children who do not identify with their assigned gender. For youths experiencing puberty and older adolescents, the Endocrine Society recommends that a team composed of expert medical professionals and mental health professionals manages treatment.

In 2016, Deutsch sponsored a so-called “bathroom bill” that would have forced public school students to use the bathrooms and locker rooms of their assigned gender. That bill was vetoed by former Gov. Dennis Daugaard.