WASHINGTON - JANUARY 22: Pro-choice advocates participate in protest in front of the U.S. Supreme Court building January 22, 2010 in Washington, DC. Activists from across the nation gathered to commemorate the 37th anniversary of the Roe v. Wade Supreme Court decision, which decriminalized abortion in all fifty states. (Photo by Mark Wilson/Getty Images)

The Supreme Court could signal as soon as Tuesday that it is ready to once again revisit the landmark abortion decision Roe v. Wade.

Conservative legislatures in states like Georgia and Alabama have in recent weeks raced to pass restrictive abortion laws in the hopes of testing the 1973 decision, which held that women have a qualified constitutional right to end their pregnancies.

Much of that legislation was spurred by the confirmation of Justice Brett Kavanaugh, President Donald Trump's second appointee to the panel, in October. The addition of the judge gave the court a reliable conservative majority.

The newly passed laws are unlikely to make it before the top court anytime soon. It could be two or three years before any litigation makes it through the lower courts.

But two laws limiting abortions passed in Indiana in 2016 and signed by then-Gov. Mike Pence, now the vice president, are ready for review. The justices on Thursday met in a private conference to vote on whether to hear them, and an announcement is expected Tuesday. It requires four votes for the court to take a case.

One of the Indiana laws prevents abortions sought for reasons deemed "discriminatory" — for instance, those based on the expected race or disability of the fetus. The other requires an ultrasound at least 18 hours in advance of an abortion.

Both laws were blocked by lower courts before going into effect, but experts say that the Supreme Court is likely to uphold any but the most restrictive abortion laws if it decides to formally review them.

"You have three pretty solid votes to uphold most of this, one very likely vote, Kavanaugh, and the chief justice, [but] he could be peeled off now and again," said Brian Fitzpatrick, a former clerk to Justice Antonin Scalia who teaches law at Vanderbilt University. "I would put my wagers on upholding most of these laws."

While the five conservative justices may avoid a complete overturning of Roe or a later decision which narrowed it, taking up either Indiana law would signal that the court intends to hamstring some longstanding protections. In Planned Parenthood v. Casey, the court reasoned that laws which put an "undue burden" on women seeking abortions are impermissible.

The possibility that Roe could be weakened but not eliminated is more alarming for some reproductive rights groups than its direct reversal. Those groups worry that upholding restrictive abortion laws could have just as grave a practical impact without sparking the same degree of political resistance as taking Roe on directly.

"We don't need to see a reversal of Roe v. Wade for states to shut their last clinic and huge numbers of people have their right to access abortion taken away from them," an attorney for the American Civil Liberties Union, which has fought many abortion restrictions in court, recently wrote.

Another abortion law the justices are likely to review soon was passed in Louisiana. In February, the justices voted 5-4 to temporarily block the law, which would have required abortion doctors in the state to have admitting privileges at a nearby hospital. The measure is nearly identical to a Texas law the court struck down in 2016.

The court's February decision has spurred intrigue. In 2016, Chief Justice John Roberts joined the conservatives in dissenting from the court's 5-3 decision to strike down the Texas version of the law. In February, though, he joined the court's liberal wing in blocking it, raising questions about which side he will take if the case comes back to the court next year for a full hearing.

Louisiana asked earlier this month for the court to hear the case, though that petition was not up for a vote Thursday.

If the court takes up the Indiana or Louisiana abortion cases, they will likely be heard in the term that begins in October. A decision would be expected around June 2020 — setting up a fight over abortion just months before Americans head to the polls in the presidential election.