As my cameraman and I approached the US Supreme Court on Wednesday, the noise got louder and louder.

Hundreds of protesters, from both sides of the abortion debate, had gathered outside the court while the justices heard arguments in the US's most significant abortion case in decades.

The outcome could have major implications for millions of women across the US.

One of the protesters, Anne Thomas, told me she was there to show her support for the protection of life, adding that the conservative Supreme Court Justice Amy Coney Barrett was a great example of success for women, a role model for her daughters, she said.

"But what about a woman's right to choose?" I asked.

"Let's talk about what we are choosing," she replied. "That choice is to end a human life, there is no two ways about it."

On the other side of the protest line, Amanda Livingstone told me she was demonstrating outside the court calling for the protection of women's rights.

"We need to have access to safe, legal, respectful abortion services and we need to trust women to make their own decisions," she said.

She also said it was absurd that former US president Donald Trump was able to pack the Supreme Court with conservative justices.

Gesturing to the louder, larger group of pro-life protesters she said: "This is scary stuff!"

Activists with The Center for Popular Democracy Action hold photos of US Supreme Court justices as they block an intersection during the demonstration

The chants were so loud they could no doubt be heard inside the court where the justices were examining a 2018 law in the southern state of Mississippi that prohibits most abortions after 15 weeks of pregnancy - a dramatic break from 50 years of established law.

The landmark 1973 Roe v Wade ruling legalised abortion in the US striking down state laws that restricted the procedure.

A 1992 decision ruled that states could not place an "undue burden" on women seeking abortions before foetal viability.

But in court on Wednesday the state of Mississippi argued that those cases haunt the country, have no basis in the constitution and poison the law.

The conservative justices on the court, who have a solid majority, appeared to signal that they would uphold the Mississippi abortion ban.

Justice Brett Kavanaugh listed several previous cases when the court had overruled long-standing precedents and also suggested that maybe the Supreme Court should withdraw from the entire abortion debate altogether.

"Why should this court be the arbiter rather than Congress, state legislatures, state supreme courts and the people?" he asked.

The three liberal justices on the bench warned that the Supreme Court would appear to be politically motivated if it overturned abortion rulings that the country had relied on for decades.

"It is particularly important to show that what we do in overturning a case is grounded in principle and not social pressure," Justice Stephen Breyer said.

During my four years here in the US, I have been struck by how politically divisive the issue of abortion is, from grassroots protest movements all the way to the White House.

Donald Trump promoted pro-life policies during his presidency, much to the delight of his conservative base.

But in Joe Biden's first days in office, he signed executive orders overturning Trump-era restrictions on abortion.

A ruling in the case that was heard on Wednesday is expected to be issued in June and depending on the outcome, at least 21 US states are getting ready to bring in more restrictive abortion laws.

It will be one of the most closely watched Supreme Court decisions in decades, not least by the hundreds, if not thousands, of protesters who will once more gather on the steps of the court.