By Joe Whittington and Andrew Harris

Two states that enacted the most restrictive abortion laws in the nation asked a federal appeals court to override the U.S. Supreme Court's landmark 1973 decision protecting women's rights to end pregnancies.

The states' attorneys' arguments seeking to uphold the laws were met with skepticism Tuesday by a panel of three judges in St. Louis, each appointed by Republican President George W. Bush.

North Dakota's law, limiting abortion availability after the sixth week of pregnancy if a fetal heartbeat can be detected, and an Arkansas statute curbing abortions at 12 weeks, were each deemed unconstitutional and struck down by lower court judges last year.

Lawyers for the states told the appellate panel it should disregard the high court's 42-year-old Roe v. Wade decision and later rulings that women have a right to the procedure under the U.S. Constitution until that point in a pregnancy where a fetus is capable of surviving outside the mother, generally accepted as about the 24th week.

"The centuries-old standard to show life is a heartbeat," North Dakota lawyer Daniel Gaustad told the court.

"Has the Supreme Court ever used or mentioned the term 'heartbeat' as a standard?" asked U.S. Circuit Judge Duane Benton, who was selected by Bush in 2004.

U.S. states have adopted more than 200 abortion restrictions since a Republican-led push began four years ago.

The Arkansas and North Dakota cases come before the panel just a week after a federal appeals court in New Orleans was asked to rule on the constitutionality of Texas laws heightening the standards under which abortion clinics can operate and requiring doctors who perform the procedure to have admitting privileges at a local hospital.

Joining Benton on the St. Louis panel were U.S. Circuit Judges Lavenski Smith, who was named to the bench in 2001, and Bobby E. Shepherd, selected in 2006.

"Viability seems to be a scientific or medical decision, not one for judges to decide," Shepherd told Arkansas attorney Colin Jorgensen. The Arkansas case is Beck v. Edwards, 14-1891, U.S. Court of Appeals for the Eighth Circuit (St. Louis). The North Dakota case is MKB Management v. Stenehjem, 14-2128, U.S. Court of Appeals for the Eighth Circuit (St. Louis).

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