Emma Gifford, 22, the daughter of retired Rank Organisation chief executive Michael Gifford, had felt unable to tell anyone about the pregnancy, which followed the birth of another child she had given up for adoption 14 months earlier.
The first her family knew of the second birth, last April, was when her brother eventually found the baby's body in the freezer at her flat in South Kensington, south-west London. Family support groups described the case as "tragic".
Initially, there was insufficient evidence for police to bring a charge of infanticide. But Gifford later made a full confession in an attempt to recover from the double trauma of the death and the adoption of her first son, William Boyce, prosecution counsel, told the Old Bailey in London.
Gifford, who the court heard had suffered from depression since she was13 and had dropped out of university, was able to keep the pregnancy secret because she barely showed any physical signs.
One night last April she returned from her work at a florists at about midnight and gave birth on the bathroom floor two to three hours later. She agonised over the secret baby until 5pm the next day. "She felt as though she had no option. She didn't know what to do," Mr Boyce said.
She told police that she placed a flannel over the baby's face, covered his head with a pair of her boyfriend's pyjama bottoms and then put a pillow over his head for a couple of minutes. She was sick, then got ready for work, later wrapping the body in clothes and a plastic bag. After confessing, Gifford pleaded guilty to infanticide.
Rebecca Poulet QC, defending, said that during childhood Gifford had been caught between an alcoholic mother and an absent father who worked long hours.
Sir Lawrence Verney, the Recorder of London, told Gifford: "The law realises that immediately at and after giving birth there may be a time when the balance of the mother's mind is disturbed by reason of her not having recovered from the effects of giving birth." Her decision to go to the police was "very much to your credit".
Another charge of attempting to conceal the birth was ordered to lie on the file.
Emma Gifford discovered that she was expecting the first child in 1994 but did not dare to tell either her boyfriend, Joseph Ernst, a former architecture student at university, or her father, and gave birth in hospital without the support of friends or family.
A long search for an adoptive family and Mr Ernst's decision to split up with Gifford took its toll on her state of mind and was to contribute to her deep trauma when she discovered that she was again pregnant by Mr Ernst in 1995.
A spokeswoman for the Family Planning Association said: "The case does emphasise the need to make sure that young people know there are agencies designed to listen and provide support in this kind of situation. It is just tragic that this young woman didn't feel she could turn to them for help."Reuse content