A saline solution was injected into Gianna’s mother’s womb, which doctors thought would kill the foetus within hours.
This time, most unusually, the procedure failed and Gianna was born alive, thanks in part to a shocked nurse.
She was so taken aback by Gianna’s live delivery that she summoned an ambulance to whisk her from the abortion clinic to the hospital.
She weighed only two pounds at birth and needed to stay in hospital for nearly three months.
In an ironic twist of fate the abortionist had to sign her birth certificate.
Now American-born Gianna, aged 28, is in London to give her message against abortion.
Pro-choice groups say that while hers is a distressing story it is unusual and that guidelines are in place in the UK to stop live births after abortions.
The legal limit for abortion in the UK is 24 weeks. The only exceptions to this is where a woman’s life is in danger or if there is a real risk that the child, if born, would have a severe physical or mental disability.
In those cases, there is no legal time limit.
Gianna, a committed Christian, is opposed to abortion.
She has cerebral palsy as a direct result of the procedure carried out on her in the womb.
“The saline solution injected into the mother is to burn the baby, which gulps it in the womb,” she said.
“But after being literally burned alive for 18 hours I was delivered live.
“It says on my records that I was born after a saline abortion.
“I was not expected to be delivered live but fortunately for me the abortionist was not in the clinic when I arrived alive instead of dead.
“I was born about 6am and my ‘birth’ was not expected until about 9am, when he would be arriving for his office hours.
“There were many witnesses to my entry into this world.
“My biological mother and other young girls at the clinic, who also awaited the death of their babies, were the first to greet me and I am told this was a hysterical moment.”
Initially the prognosis for Gianna, who comes from Tennessee, was poor.
Because of her cerebral palsy her foster mother was told that she was unlikely to ever crawl or walk.
She, however, was determined and eventually learned to sit, crawl and then stand.
She started to walk with leg braces and by the age of four was walking with the aid of a walker – now she walks without any assistance.
She refuses to let her cerebral palsy blight her life and is currently training for the London marathon.
But she says her determination can cause her problems.
“I am often misunderstood, which is often the most painful.
“My determination not to give up is often misunderstood as being over confident.
“But it is not that. I am just determined not to give up. I am just not a quitter.
“Being almost murdered in the womb and then having to struggle from the moment I was delivered means I have a love of life and a joy of life.”
Gianna has never met her biological mother, but her adopted mother has and passed on Gianna’s forgiveness.
Her biological parents were both just 17 when Gianna was born.
She is in London this week to lend her voice to the anti-abortion group ‘Alive and Kicking,’ who are campaigning to encourage reform of the Abortion Act aimed at reducing the annual number of abortions.
This week Gianna will speak at a parliamentary meeting at the House of Commons to tell her remarkable story.
And she hopes hearing her story will persuade others to consider the rights of the unborn child.
“What happened to me was all being done in the name of women’s rights, but the only one who cared about my rights was the nurse in the clinic, who got me the heck out of there.
“My mother was making a decision that was ‘only hers to make’, but I bear the scars of that.
Citra Abbott Spokesperson for Alive and Kicking said: “Gianna is bearing witness to the humanity of the unborn child and to the right to life of every human being.
“She is also a powerful witness to the rights of the disabled. ”
Ann Furedi, chief executive of the British Pregnancy Advisory Service, said it was important to remember that late abortions, like that of Gianna’s mother, are uncommon.
“These stories are extremely distressing. But the point we would always make is that these very late abortion at times when there is a potential for life are very few and far between.
“And there is very clear guidance to make sure this sort of thing does not happen.”
She added that cases like Gianna’s were now less likely to happen because of advancing technology and tightened regulations, and that when a woman opted for a late abortion it was usually because the babies had a foetal abnormality.
“If women have a wanted pregnancy and go into labour prematurely they need to know that everything will be done to their babies, but if they need to have an abortion at this late stage then the intention will be that there is not live birth and the procedure should avoid a live birth.”