On Wednesday, demonstrators once more filled Buenos Aires' streets - with some supporters of the bill saying more than 1 million people may attend the planned vigil outside Congress.
Fireworks and shouts of joy erupted among anti-abortion activists camped outside Congress, while pro-choice campaigners, many decked in the green scarves that had come to symbolize their movement, were downcast.
In the Senate it is widely expected to fall short of the votes needed to pass, with 37 of the 72 senators said to be ready to say no despite a massive social campaign to have it adopted.
Argentine women can still obtain legal abortions, but only in limited cases, like rape or if the health of the mother is in jeopardy.
Rallies took place around the world in front of Argentine diplomatic missions, mainly in support of the bill. According to the Guardian, an estimated 3,000 Argentine women have died as a result of illegal abortions since 1983, and between 45,000 and 60,000 women are hospitalized annually as a result of complications from illegal abortions. Now that the bill has failed, lawmakers can not resubmit legislation until next year.
Jose Miguel Vivanco, director for the Americas at Human Rights Watch, said Argentina has a "historic opportunity" to protect the rights of women.More news: Trump calls for peace on Charlottesville anniversary as residents on edge
Activists say they'll keep pushing the bill, in the hope that it passes one day soon.
The debate in the Senate went on for more than 16 hours and was reportedly very passionate at times. "We won because we looked at each other eye-to-eye and we realized how strong we are, and that abortion will eventually be legal".
Senator Norma Durango from the Justice Party said she would work "until the last minute so that this becomes law", warning that those who vote against the bill would be "responsible for continuing deaths".
"The ones behind the pro-abortion campaign are people who have economic power, particularly in Buenos Aires", Camila Duro, member of nongovernmental organization Frente Joven, part of the "Let's save both lives" campaign, told CNN.
In recent weeks the so-called "green wave" demonstrations have spread outside of Argentina too.
Supporters of the bill held protests for months under the banner of Ni Una Menos, a coalition of women's rights groups.
Pope Francis this year had denounced abortion as the "white glove" equivalent of the Nazi-era eugenics program and urged families "to accept the children that God gives them". George Soros has also been a major player in the financing of pro-abortion lobbyists through his Open Society foundations.
Adolfo Rubinstein, Argentina's health minister who has argued for legalization, attempted to present abortion as a health emergency publicly by stating unsafe abortion is the country's leading cause of maternal death.