The US Supreme Court on Monday refused to review a case involving North Carolina's law that would compel a woman to receive a narrated ultrasound report before getting an abortion, a procedure that was declared unconstitutional by lower and appeals courts.

In 2011, the North Carolina legislature passed the Women's Right to Know Act requiring women seeking abortion to have an ultrasound and to attend a session with her doctor who would place the ultrasound image in front of her and describe it in detail.

Then-governor Beverly Purdue vetoed the legislation but it was overridden by the legislature.

The American Civil Liberties Union (ACLU), the Center for Reproductive Rights and the Planned Parenthood Federation of America then filed a lawsuit to block the implementation of the law.

US District Judge Catherine Eagles declared the law unconstitutional in a ruling in January last year, saying that it was "an impermissible attempt to compel [abortion] providers to deliver the state's message in favour of childbirth and against abortion."

Last December, the Fourth Circuit Court of Appeals upheld the ruling, saying the ultrasound law violated the First Amendment.

"This compelled speech, even though it is a regulation of the medical profession, is ideological in intent and in kind," the appeals court declared. "The First Amendment not only protects against prohibitions of speech, but also against regulations that compel speech. A regulation compelling speech is by its very nature content-based, because it requires the speaker to change the content of his speech or even to say something where he would otherwise be silent."

The court added, "Moreover, the statement compelled here is ideological; it conveys a particular opinion. The state freely admits that the purpose ... is to convince women seeking abortions to change their minds or reassess their decisions."

The decision was appealed to the US Supreme Court which refused to review it.

Pro-life groups were disappointed with the US Supreme Court's decision to let the appeals court ruling stand.

"In any other medical procedure, doctors would have a duty to disclose all of the relevant information, and, yet, a procedure as destructive and life-changing as abortion is held to a lower standard," said Tami Fitzgerald of the North Carolina Values Coalition.

"We're disappointed that the Supreme Court has decided not to review a decision that denies mothers this fully informed consent about human life in the womb and the methods abortionists use to end it," said Alliance Defending Freedom (ADF) Senior Legal Counsel Steven Aden in a statement.

However, ACLU North Carolina lauded the Supreme Court's action, or lack of it, saying that "North Carolinians should take comfort in knowing that this intrusive and unconstitutional law, which placed the ideological agenda of politicians above a doctor's ability to provide a patient with the specific care she needs, will never go into effect."

Mark DeFrancesco, president of the American College of Obstetricians and Gynecologists, also said the law contradicts best medical practices.

"Laws that force physicians to subject patients to non-medically indicated ultrasounds—and to display and describe those ultrasounds—run counter to best medical practices and are simply wrong. Moreover, this law violates the principle of appropriate informed consent," he said.