The proposal, which was put forward jointly by the DUP and SDLP, fell as expected following a vote on Tuesday.
It was backed by 53 elected members, including 44 unionists and nine nationalists, however it was defeated on a cross-community basis with 40 votes against.
Ahead of the debate in the Assembly chamber, Speaker Willie Hay warned all parties that the issue was a deeply sensitive and emotive one which required moderate language.
But proceedings still became heated throughout what was a lively and lengthy discussion on the proposed criminalisation of abortions in NI outside of the NHS - while outside a petition was delivered to Stormont by anti-abortion campaigners.
The DUP accused Sinn Féin of being ideologically and morally bankrupt, with Sinn Féin countering that those bringing the amendment should be ashamed of themselves.
Lagan Valley DUP MLA Paul Givan, who proposed the amendment alongside Alban Maginness of the SDLP, held that there was significant support for those seeking to oppose abortion.
"Across the island of Ireland, we have a common bond in seeking to provide the best care for our mothers and unborn babies," he said.
"The NHS is where vulnerable women and their unborn babies should be treated, not a private clinic making financial gain. It ensures that in terrible life-threatening circumstances the best care is provided - free."
If this is the backwoods, I'm glad we're in it.
Edwin Poots, DUP
SDLP MLA Patsy McGlone also stated that the amendment "reflects the widespread support for the strict regulation of abortion both here in the north and indeed across the island of Ireland".
He added: "The pro-abortion lobby are keen to push the boundaries of the law on this issue."
But Sinn Féin's Caitríona Ruane claimed that it shouldn't matter where a termination took place, as long as it was carried out within the law as it stands.
She insisted that her party was not in favour of abortion, but supported terminations being made available in cases of rape, incest or threat to the life of the pregnant woman.
"In Sinn Féin's view, in an ideal world, all aspects of health would be dealt with in the National Health Service," Ms Ruane said.
"The reality, of course, is that the National Health Service is currently heavily dependent on private health referrals, from the NHS to private clinics."
She further added that the amendment was simply an attempt to shut down the Marie Stopes sexual health clinic in Belfast by the back door.
Are we to wait for another tragedy before those who brought this amendment forward will cease to play with the lives of women?
Caitríona Ruane, Sinn Féin
Many side issues were raised throughout the debate - including whether it was for a male-dominated Assembly to rule on an issue affecting women and what implications any changes to the law would have in terms of emergency cases where the NHS could not provide support.
Concerns were also raised over differing views on when life begins - amid questions over the impact on some forms of contraception if life was taken to mean from the moment of conception and the current legislation was changed.
Alliance Party leader and Justice Minister David Ford told those gathered in the chamber that he was concerned that members of the public may have believed that the debate was one of pro-abortion versus pro-life or pro-choice.
"It is not. It is about a very technical issue of the law," he said.
Mr Ford raised concerns about cases, however infrequent, where the wording of the amendment could cause problems - for instance, if a woman was referred by the NHS to a private clinic, but later suffered complications which meant a termination was essential and for which she would therefore need to be transferred back to an NHS hospital to avoid breaking the letter of the law.
This is not a pro-abortion versus pro-life debate.
David Ford, Alliance
But the Alliance Party's South Belfast MLA Anna Lo and the Green Party's Steven Agnew both came under fire from the DUP for siding with Sinn Féin in signing the petition of concern against the proposed amendment.
"I am pro-choice," Ms Lo said, in response to criticism.
"I believe women have the right to decide what to do with their bodies. It's not for men in this House to tell them what to do."
Ms Lo added that those claiming the Marie Stopes clinic was trying to sneak abortion into Northern Ireland through the back door were doing the same thing when it came to the amendment.
"Without public consultation, you are sneaking this amendment in through the back door," she said.
Abortion is currently illegal in Northern Ireland except in extreme cases where there is said to be severe risk to the life or mental health of the pregnant woman.
Around 1,500 women from Northern Ireland are said to have travelled to England for a surgical abortion in recent years. Abortion pills have also been accessed online, without medical supervision.
Marie Stopes, a registered charity, provides a range of services in its clinics - from scans to STI testing and contraceptive advice. It also offers medical, non-surgical abortions carried out before the ninth week of pregnancy.
You talk about democracy. Is it democracy to ask women to carry out a pregnancy that was the result of rape?
Anna Lo, Alliance
But members of the DUP and SDLP moved to discredit the organisation, insisting that it was unregulated and seeking to exploit a gap in the law.
Health Minister Edwin Poots, speaking only in his capacity as a DUP MLA for Lagan Valley, asked: "Was there a gap in the market where the health service wasn't meeting the needs of women before Marie Stopes came to Northern Ireland?"
He further added that the lack of regulation for Marie Stopes meant that "nobody knows if the law is being breached because Marie Stopes is operating under a cloak of darkness".
UUP MLA Tom Elliott expressed concern that "while we're stopping this amendment going forward, we're actually allowing and permitting abortions to take place without any regulation".
But Green Party leader Steven Agnew held that the amendment would only restrict choice for women without considering their individuals cases and needs.
"I cannot claim to speak for the majority of women," he said.
"So I seek to afford them choice. This amendment restricts their choice. It doesn't not seek to regulate, it seeks to ban and it is aimed only at one provider (Marie Stopes)."
As a petition of concern has been raised on the issue of changing the law - signed by Sinn Féin, the Alliance Party and the Green Party - cross-party consensus is needed for the amendment to be passed by the Assembly.
TUV leader Jim Allister accused those backing the petition of concern of manipulation and added: "The one thing that is being aborted today in this house is democracy."