A “cold and calculating” mother has been jailed for eight years after robbing her unborn baby boy of his chance of life when she aborted him within a week of his due date.
Sarah Catt, who was married but had been having an affair for seven years, was around 40-weeks pregnant when she took drugs she bought on the internet to induce her labour.
She claimed the baby was stillborn and she buried his body, but has since refused to tell anyone where to find her son.
Catt, who showed no emotion during the hour-long sentencing, was described as "cold and calculating" by police, who searched her home with dogs and specialist equipment to try to find the child's body.
Mr Justice Cooke said the seriousness of the crime lay between manslaughter and murder.
He said she would have been charged with murder if the baby had been born a few days later and she had then killed him.
"The child in the womb was so near to birth that, in my judgment, all right-thinking people would consider this offence more serious than manslaughter or any offence on the calendar other than murder," he said.
"What you did was end the life of a child that was capable of being born alive, by inducing birth or miscarriage."
He added: "What you have done is rob an apparently healthy child, vulnerable and defenceless, of the life which he was about to commence."
Mr Justice Cooke said Catt ended the pregnancy with full knowledge of her due date and of the abortion law.
He said: "This was a cold, calculated decision that you took for your own convenience and in your self-interest alone."
Catt, 35, from Sherburn-in-Elmet, North Yorkshire, had previously given a baby up for adoption and terminated a pregnancy with the agreement of her husband.
She also attempted to terminate another baby but was beyond the legal limit of 24 weeks and concealed a further pregnancy from her husband before the child's birth.
When she discovered she was pregnant again in 2009, she believed the father of the child was her lover and ended the relationship after telling him about the pregnancy. She restarted the "casual" affair in June the following year.
She had an appointment for a consultation at a Marie Stopes clinic on March 16 2010 but a scan the day before showed that she was 29 weeks five days pregnant and too late for a termination.
Between March and May, she made several searches on the internet about illegal abortions and abortion drugs, including "Where can I get an illegal abortion?" and "Inducing an abortion at 30 weeks".
She bought drugs online from a company in Mumbai, India, in April 2010.
The drug was delivered to her home address when she was 38 weeks pregnant and around 11 days later, on May 21, she asked on the internet what would happen if she took the drug at full-term. On May 26 she asked how soon the drug would work.
Mr Justice Cooke said: "It's a fair inference you must have taken the drug somewhere around that time."
Catt told a psychiatrist she had taken the drug while her husband was away and delivered the baby boy, who was not breathing or moving, by herself at home.
She went on a family holiday to France on May 27. She did not tell her husband about the pregnancy and did not tell anyone about the baby.
Catt was arrested in September 2010 and was interviewed several times over the next year.
She told police she had undergone a legal abortion at a Marie Stopes clinic in March of that year - despite being nearly 30 weeks pregnant at that stage.
She pleaded guilty earlier this year to administering a poison with intent to procure a miscarriage.
Speaking after the sentencing, Chief Inspector Kerrin Smith, of North Yorkshire Police, said: "This was an unusual, disturbing and very complicated case to investigate.
"Catt has proved to be cold and calculating, and has shown no remorse or given an explanation for what she did, lying to the police, health professionals and her family throughout the investigation."
The detective added: "I only hope now that Catt has been sentenced and has the time to reflect on her actions, that she will reveal where the body of her baby is, so that we can ensure a compassionate conclusion to this very sad investigation."