COLUMBIA, S.C. (AP) — With a heartbeat abortion ban solidly in place in South Carolina, lawyers for the state and Planned Parenthood return to the state’s highest court Wednesday to argue how restrictive the ban should be.

The law is being enforced in South Carolina as a ban on almost all abortions around six weeks after conception, setting that mark as the time cardiac activity starts.

But Planned Parenthood and other abortion rights groups are arguing the 2023 law includes alternative definitions about the timing of a fetal heart forming and a “heartbeat” starting and the true ban should start around nine or 10 weeks.

Both sides are set to argue for just over an hour at the South Carolina Supreme Court in Columbia. The justices likely will take several months to decide the case. In the meantime, the abortion ban around six weeks likely will remain in place after a lower court upheld it.

The 2023 law says abortions cannot be performed after an ultrasound can detect “cardiac activity, or the steady and repetitive rhythmic contraction of the fetal heart, within the gestational sac.”

South Carolina and several other states place that at six weeks into development. But what follows the “or” in the sentence could require that a heart has formed, and medical experts say that doesn’t happen until around nine weeks.

The legal fight has been brewing since the state Supreme Court reversed itself after overturning a similar ban in 2021. The Republican-dominated General Assembly then made small changes and a justice who voted in the majority in the 3-2 decision to overturn the ban reached retirement age and was replaced.

In the decision upholding the new ban, the state Supreme Court itself noted the different definitions saying resolving them would be a question “for another day.”

That day is Wednesday. Since then, more inconsistencies in the law’s language have been brought up. The law refers to a fetal heartbeat, but most experts consider a fertilized egg to be an embryo for about 10 weeks after conception before transitioning into a fetus.

Lawyers for the state said the parsing of the language ignores the intent of the Legislature. Both supporters and opponents of the bill called it nearly exclusively a six-week ban during debate in the House and Senate.

Since the U.S. Supreme Court overturned Roe v. Wade in 2022 and ended a nationwide right to abortion, most Republican-controlled states have started enforcing new bans or restrictions and most Democrat-dominated ones have sought to protect abortion access.

Currently, 13 states are enforcing bans on abortion at all stages of pregnancy, with limited exceptions, and South Carolina and three others have bans that kick in at or about six weeks into pregnancy — often before women realize they’re pregnant.

The latest lawsuit was filed by South Carolina resident Taylor Shelton, who said she had sought medical attention for pain from her intrauterine device and was stunned to find out, just two days after missing her regularly-tracked period, that she was pregnant.

She ended up in North Carolina, driving for hours to several appointments to undergo an abortion because doctors in South Carolina were unsure how to define a heartbeat. Shelton couldn’t be completely sure she was within six weeks.

Some Republicans in South Carolina are also pushing for an outright abortion ban, but while legislation was introduced this January when the General Assembly started its two-year session, no hearings have been held.