By Terry Baynes

(Reuters) - A Texas law requiring abortion providers to show or describe an ultrasound image to a woman of her pregnancy and to play sounds of the fetal heart does not violate the U.S. Constitution, a federal appeals court ruled on Tuesday.

The court ruled that the ultrasound requirements do not infringe on abortion providers' free speech rights, overturning a lower federal court's decision.

"The required disclosures of a sonogram, the fetal heartbeat, and their medical descriptions are the epitome of truthful, non-misleading information," Chief Judge Edith Jones wrote for the three-judge panel.

The Texas law, enacted in 2011, requires abortion providers to display the ultrasound images and describe them in detail. While a woman seeking an abortion can decline to view the legally required ultrasound, she cannot decline to hear the physician's description of it unless she qualifies for an exception due to rape, incest or fetal abnormality.

A coalition of medical providers sued in June to block the law, arguing that it made doctors a "mouthpiece" for the state's ideological message. The First Amendment includes protections against compelled speech.

The challengers, represented by the Center for Reproductive Rights, also argued that disclosure of the sonogram and fetal heartbeat was not "medically necessary" and therefore beyond the state's power to regulate the practice of medicine.

A federal judge in Austin ruled that the law violated physicians' free-speech rights. But the U.S. Court of Appeals for the 5th Circuit disagreed.

"Only if one assumes ... that pregnancy is a condition to be terminated, can one assume that such information about the fetus is medically irrelevant," the judicial panel concluded.

The panel cited a 1992 decision in Planned Parenthood v. Casey in which the Supreme Court upheld a law requiring abortion providers to inform pregnant women of relevant health risks and the gestational age of the fetus. The high court ruled that doctors could be required to provide information that is truthful, not misleading and relevant to the decision to have an abortion.

The president of the Center for Reproductive Rights, Nancy Northup, said in a statement the decision "clears the way for the enforcement of an insulting and intrusive law whose sole purpose is to harass women and dissuade them from exercising their constitutionally protected reproductive rights."

The Texas law is among the most extreme ultrasound requirements in the country. Similar laws requiring the presentation of an ultrasound image to pregnant women have been blocked in Oklahoma and North Carolina.

Six other states also require abortion providers to perform an ultrasound and provide women with an opportunity to view the image, according to the Guttmacher Institute, which specializes in research on reproductive issues. But unlike Texas, those states don't require women to hear a description of the image.

The Office of the Solicitor General, which represented the Texas officials, did not immediately respond to requests for comment.

Texas Governor Rick Perry, while campaigning for the Republican nomination for president, praised the ruling as a victory. "This important sonogram legislation ensures that every Texas woman seeking an abortion has all the facts about the life she is carrying," Perry said in a statement.

(Reporting by Terry Baynes; Editing by Daniel Trotta and Jackie Frank)