A new law in Utah is forcing abortion doctors to render their patients unconscious to ensure that the foetus does not feel “pain’”.

The “Protecting Unborn Children Amendment” aims to “eliminate or alleviate organic pain to the unborn child”, arguing that a foetus can feel pain after 20 weeks – a claim that is not backed up by science.

Republican Senator Curt Bramble told lawmakers he would ban abortions if he could, but the US Supreme Court has blocked this path.

“This will require that if we are going to take the life of an unborn child,” he said, as reported by the Salt Lake Tribune, “then anaesthesia would be required to protect the child from the infliction of pain at the time their life is forfeit.”

The law does not require doctors to inform women of the risks and side effects of receiving an anaesthetic which, medical experts argue, their patients do not need.

“You’re asking me to invent a procedure that doesn’t have any research to back it up,” Dr Leah Torres, who works at one of Utah’s two licensed abortion clinics, told the New York Times. “You want me to experiment on my patients.”

Providers do already offer anaesthesia to patients seeking later term abortion, but it is not compulsory and doctors must inform women of the possible risks.

Dr Torres said there is no guidance in the new law on what kind of drug – or how much – should be administered to patients, as the law has been compiled by politicians and not medical experts.

Doctors are also required to tell patients that “substantial medical evidence from studies concludes that an unborn child who is at least 20 weeks gestational age may be capable of experiencing pain during an abortion procedure.”

A study published in the Journal of the American Medical Association found that a foetus does not develop the ability to feel pain before 29 or 30 weeks.

Doctors say the law is not medically possible, according to the Salt Lake Tribune, yet if they refuse to follow the new law, doctors could face a third-degree felony.

At least 12 states have tried to ban abortion after 20 weeks altogether, and failed, as reported by Think Progress. However, the new law in Utah, the first of its kind in the US, might as well be a ban as it could deter doctors from performing the procedure altogether.

“Imagine that I sit down with a patient and tell her what she can expect and how I'm going to take care of her,” Dr Anne Davis, consulting medical director for Physicians for Reproductive Health, told CNN. “And somehow I work in, 'Oh, by the way, the state has told me that I have to give this to you?' She asks, 'Why?' And I say, 'There's no benefit to you, but there will be additional risk.’”

A study by Rutgers University in February found that a third of women who get leaflets on abortion from the state are being misinformed. In North Carolina, women are told that foetus between 12 and 14 weeks have fully formed lips, noses and fingernails are starting to grow.

A March study discovered that 70 per cent of recently introduced state abortion restrictions are based on false information.