In short:

South Australia's upper house has voted down proposed changes to current abortion laws.

Liberal MP Ben Hood introduced amendments to the current abortion laws so people would be induced after 27 weeks and six days instead of receiving a termination.

What's next?

The bill will not go to the lower house and will not become law.

South Australia's upper house has narrowly voted down a proposal to amend abortion laws that would have required people wanting to terminate their pregnancy after 28 weeks to deliver their baby alive.

The amendments, proposed by Liberal MP Ben Hood, would have required women seeking to terminate a pregnancy from 28 weeks to instead undergo an induced birth, with babies to then be adopted.

Under legislation passed in 2021, a pregnant person can get a late-term abortion after 22 weeks and six days if it is deemed medically appropriate and approved by two doctors.

According to SA Health, in the first 18 months after the legislation was implemented, "fewer than five" people had their pregnancies terminated after 27 weeks.

Both major parties allowed a conscience vote on the private member's bill, meaning that MPs did not need to vote along party lines.

After around 3 hours of debate on Wednesday evening, the bill was defeated just before 10pm — nine members voted in favour of the bill and 10 against.

Parliament controversy

The vote was marred by disagreements between MPs, that resulted in a Liberal MP who was home on sick leave making a last minute dash to parliament to ensure her vote was counted.

Ms Lensink was away from parliament for the debate, because she is undergoing treatment for breast cancer.

She was a major proponent of the 2021 laws that decriminalised abortion in South Australia, and is strongly opposed to the changes being pushed by conservatives in her party.

She told ABC Radio Adelaide she was initially granted a pair arrangement by a Liberal Party colleague, Jing Lee.

Under that arrangement Ms Lee, who was in favour of the bill, would abstain from the vote, meaning the outcome wouldn't been affected by Ms Lensink's absence.

But Ms Lensink said about half an hour before the vote, Ms Lee told her she would no longer be her pair.

Ms Lensink said she then understood One Nation MP Sarah Game would be her pair instead.

"I thought it was fixed … then I start getting more texts and phone calls from other colleagues saying not it's not," Ms Lensink said.

"I thought it might get to the point where I would physically have to go there because I felt my pair might not be honoured."

It was then Ms Lensink said she got into an Uber to rush to parliament.

Ms Lensink said while decisions like Ms Lee's happen "from time to time", she was frustrated that Ms Game did not tell her she was not going to act as her pair.

Ultimately another Liberal colleague, Dennis Hood agreed to pair with Ms Lensink.

Mr Hood said he agreed to the arrangement because Ms Lensink did the same for him when he was undergoing cancer treatment during previous debate on a bill regarding sex work laws.

"I was unable to be in the parliament, I was just too ill and I think I was in hospital at the time," Mr Hood said.

"Michelle was good enough to pair me at the time so I said to her if you ever need the favour returned I would do the right thing by you."

How debate played out

Starting off the debate on Wednesday evening, Mr Maher slammed Mr Hood's bill.

"This bill is not based on evidence, it's insulting to women and girls and above all it's dangerous in how it plays politics with the health and wellbeing of women," Mr Maher said.

Liberal MLC Dennis Hood said he supported the proposed changes, saying it was a "compassionate response for both baby and mother".

"This bill is intended to strike a balance, I think very importantly, between respecting a woman's right to terminate a pregnancy while protecting the life of a baby that would almost certainly survive outside of the womb."

Labor MLC Clare Scriven also spoke in support of the bill.

"There is a strong message in the pro-life movement, which is 'love both'," she said.

SA Best's Connie Bonaros criticised Mr Hood's position on the issue, saying there was nothing "simple" about making a decision to terminate a pregnancy.

"You do not wake up one day and decide, 'I no longer want to be carrying this baby' at that late term and expect to turn up at a specialist clinic and say 'get this out of me' and have a specialist say 'OK, let's go,'" Ms Bonaros said.

"Unfortunately, that has been the sort of public message that has been sold in this debate.

"Unless and until we've walked in the shoes of any woman facing what these women face, then we have absolutely no right to cast judgement on them."

In his speech, Ben Hood said his bill was "not about taking away a woman's rights or limiting her autonomy".

"It is about drawing a clear and humane line once a baby reaches viability at 28 weeks," he said.

Mr Hood said babies born after 28 weeks were "not condemned to a life of suffering, most will grow up healthy and thrive".

"We cannot use the possibility of some complications as a justification for ending life," he said.

"These children are not statistics, they are living breathing beings who deserve the chance to live." he said. 

Proposal sparks debate

The proposal has been met with debate within both political and broader medical circles.

The proposed amendment, which has been strongly backed by anti-abortion campaigner and University of Adelaide law professor Joanna Howe, has been met with support at rallies on Parliament steps.

It has been opposed by the Royal Australian and New Zealand College of Obstetricians and Gynaecologists (RANZCOG), with its SA committee chair Heather Waterfall labelling abortion "an essential service".

Earlier, Greens MP Tammy Franks told ABC Radio Adelaide its party position was to vote against the proposal, saying abortion should be treated as a health issue.

"Both Greens votes will be voting this bill down," she said.

In a statement, Law Society of South Australia president Alexander Lazarevich reaffirmed support for the 2021 legislation, which was informed by a report from the South Australian Law Reform Institute.

"In the society's view, a medical professional is best placed to assess the individual circumstances of a patient and treat the patient according to best medical practice standards and the ethical framework under which all medical professionals must operate," he said.

"The law ought not to unduly interfere with or restrict the capacity of medical professionals to provide appropriate, individualised and evidence-based patient care."