Jan 13 (Reuters) - A federal appeals court on Friday ordered the immediate enforcement of a new Texas abortion law that requires abortion providers to show and describe ultrasound images to pregnant women and play them sounds of the fetal heart.

A three-judge panel of the U.S. Court of Appeals for the 5th Circuit granted Texas officials' request to expedite implementation of the law. Three days earlier, the same panel had overturned a federal judge's decision to block the law, ruling that the sonogram requirements do not infringe on abortion providers' free speech rights.

Then on Thursday, Texas Attorney General Greg Abbott asked the appeals court to make its decision effective immediately, shortening the 22-day waiting period typically required under the court's rules. The appeals court granted the request in a one-sentence order less than a day later.

"There is no justification for Texas to have insisted on the immediate enforcement of this intrusive and demeaning law, nor the court of appeals to have granted it without giving us an opportunity to be heard," said Nancy Northup, president of the Center for Reproductive Rights which represents the coalition of abortion providers challenging the law.

Texas AG Abbott argued that the three-week waiting period would give challengers an incentive to ask the appeals court for a rehearing before a larger panel of judges, which could have delayed the law's enforcement for up to months.

"This court has already determined that the district court's preliminary injunction order... violates the state's constitutional prerogatives to regulate abortion," Abbott said in the state's court filing.

Carrie Williams, a spokeswoman for the Texas Department of State Health Services, said the agency hoped to implement its enforcement plan in the coming weeks. She said the department was finalizing its notification letters that it will send to abortion facilities and inspectors.

The Texas law, enacted in September 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.

The district court is scheduled to hear arguments on the constitutionality of the law next week on Jan. 20.

The case is Texas Medical Providers Performing Abortion Services et al v. David Lakey et al, U.S. Court of Appeals for the 5th Circuit, No. 11-50814.

For the Texas Medical Providers Performing Abortion Services et al: Julie Rikelman of the Center for Reproductive Rights.

For the Texas defendants: Jonathan Mitchell of the Office of the Solicitor General.

(Reporting by Terry Baynes)

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