Three years of the sentence were suspended by Justice Eugene O'Kelly who said it was a "sad and tragic" case with the woman's "grave" actions meaning her baby girl was "left to die by the one and only person who knew of her birth".
However, when handing down the sentence, the judge said that the woman, now 23, had herself acknowledged that "she has to live with consequences of what she has done and what she has failed to do for the rest of her life", in a letter handed up to the court.
He said her actions went "so much against the natural instincts of any parent", but that there was little risk of her reoffending.
The woman, who the court allowed to be named as Caitlin Corcoran, of Castleblaney, Mullinvat, Co Kilkenny, and formerly of Mount Suir, Carrickphierish in Waterford City, sobbed and was visibly shaking at various points during her sentencing hearing at Waterford Circuit Criminal Court.
Justice O'Kelly said Ms Corcoran was "very young" at 19 years old when the incident happened, and that "a young baby girl was born healthy with a chance of a long and happy life ahead of her" which was denied by what took place at the Caredoc.
He had earlier reserved making a decision as he wanted to read through psychological reports and academic research on midwifery in a newborn.
Giving his judgement, Justice Eugene O'Kelly said she benefited from a favourable probation report but had a "complex psychological profile, leaving him to ask "does society benefit" from her serving the jail sentence in full.
He said it was a "rare and exceptional" case where a significant proportion of the sentencing, pending good behaviour from Ms Corcoran.
The court heard Ms Corcoran had concealed her pregnancy and had tampered with pregnancy tests in a bid to avoid her family finding out.
Justice O'Kelly said one psychiatric report found that Ms Corcoran had suffered bullying in childhood.
"She learned how to deal with overwhelming aspects of the world by ignoring them," he said, which the report found "helped her to escape" and resulted in her entering "subconscious denial of her pregnancy like she did in childhood".
In her letter to the court, she said she wanted to give it an understanding of her personal circumstances during her pregnancy.
"I was in such a state of denial that night. I am living with the consequences everyday and will be as long as I live.
I deeply regret what happened and wish things could have turned out differently."
In sentencing, the judge said he was not considering the concealing of the pregnancy an aggravating factor and instead focused on the 13 minutes the woman spent inside the toilet cubicle at Caredoc, after presenting with severe back pain and constipation.
He said the appropriate sentence for the manslaughter and the charge of child neglect were four years each, to run concurrently, which he reduced by nine months in each case.
Gardaí were originally notified after doctors at University Hospital Waterford found indications that she had recently given birth, following the woman getting referred by a GP at Caredoc.
A search of the medical centre found the body of a full-term baby girl in a bin, a number of hours after the girl was born.
The court heard that while she was at Caredoc, Ms Corcoran went into the toilet and gave birth to a baby girl.
She placed the baby in a bin and returned to the doctor’s room but said nothing about the baby.
The court heard she saw blood "gushing" between her legs before seeing the baby's feet. Justice O'Kelly said that she was asked what she did before placing the baby in the bin, and the accused said she held the newborn in her left hand and saw "how beautiful she was".
"I was looking for movement. I wanted her to cry," she told investigators.
The woman was found guilty by unanimous verdict by a jury last October.