By Terry Baynes

(Reuters) - A Texas law requiring that an ultrasound image be shown to a pregnant woman and the sound of the fetal heartbeat be played before an abortion is performed does not violate the Constitution, a federal appeals court ruled on Tuesday.

The appeals court overturned a federal judge's decision to block the law. The ultrasound requirements do not infringe on abortion providers' free speech rights, it said.

"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. Women cannot decline to hear the physician's description of the image unless they qualify for an exception.

A coalition of abortion providers sued to block the law in June 2011, arguing that the law 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 granted the providers' request for a preliminary injunction, ruling that the law violated physicians' free-speech rights. But the appeals court disagreed.

The appeals court said a 1992 Supreme Court decision allowed 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 Center for Reproductive Rights did not immediately respond to a request for comment.

The Texas law is among the most detailed of the 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. But unlike Texas, those states don't require women to hear a description of the image.

Texas Governor Rick Perry, who championed the law and is running for the Republican nomination for U.S. president, praised the ruling.

"This important sonogram legislation ensures that every Texas woman seeking an abortion has all the facts about the life she is carrying," he said.

(Reporting by Terry Baynes; Editing by Greg McCune)