Plaintiff Taylor Shelton in her lawsuit said the law's ban on abortion after "cardiac activity, or the steady and repetitive rhythmic contraction of the fetal heart" is ambiguous because it could mean either the first detectable electrical activity, around six weeks, or the formation of the heart's chambers, after nine weeks.

South Carolina passed the law in August 2023, becoming one of several states to enact so-called "heartbeat" laws since the U.S. Supreme Court in 2022 allowed states to ban abortion. Shelton's lawsuit appears to be the first challenge to such a law based on the definition of fetal heartbeat.

In the complaint against South Carolina Attorney General Alan Wilson and the state's Board of Medical Examiners, Shelton and Planned Parenthood are asking a Richland County state court to rule that the law applies after about nine weeks. They say South Carolina law requires the court to resolve the ambiguous language in their favor.

Shelton said that because doctors interpret the law to mean six weeks, she was unable to get an abortion of her unwanted pregnancy in time and was forced to travel to neighboring North Carolina, where abortion is legal until 12 weeks.

"The entire experience left me angry and quite frankly, traumatized," Shelton said in a statement. "I want everyone to understand the impact South Carolina's abortion restrictions and unfair treatment are having on real people, and I hope my story shows how punitive and cruel these abortion bans actually are."

"We've vigorously defended this law in the past and will continue to do so," Robert Kittle, a spokesperson for Wilson, said in a statement.

South Carolina Chief Justice Donald Beatty, the sole Democrat on the state's highest court, wrote that the definition of fetal heartbeat was ambiguous in his dissent from the court's ruling last August upholding the ban. The majority did not address the issue.

(Reporting By Brendan Pierson in New York; Editing by Alexia Garamfalvi and David Gregorio)

By Brendan Pierson