Alexis Bowater, 39, received a stream of threatening messages including one which read: 'I hope your baby dies'.
The former newsreader said the threats kept her awake at night and made her frightened to be at home alone without her husband.
Alexander Reeve, 24, sent her 26 messages in one five month period, leading Mrs Bowater to constantly fear for her and her children's safety.
Alexis Bowater was harassed by Alexander Reeve throughout her pregnancy.
Speaking after her tormentor admitted sending numerous emails of a violent or sexual nature, Mrs Bowater said: 'I would lie in bed at night thinking, 'Is this person going to kill me? Am I going to die?'
'I would be in an empty house with no husband around, and when you're comforting a toddler in the middle of the night and you hear a creak on the stairs, it's absolutely terrifying.
'I used to go to bed making plans of how I was going to get myself and my children out of the house if someone came in.
'It was terrifying. You wonder about the people driving in a car behind you and people in the street. Nobody knew who he was or what he looked like.'
Mrs Bowater, who presented the evening news on ITV Westcountry, said police became involved when the harassment started in 2006 but their investigations drew a blank.
The daughter of Sir Euan and Lady Bowater of Chagford said:
'Then it started again and they pieced it together.
'I've had people harassing me on and off over the years since I've been working at ITV but never, ever this aggressive and serious.'
She added: 'He was sending anonymous e-mails to work which were pretty aggressive, graphic and threatening. This went on for years.
'This last summer was the worst, the threats and e-mails were escalating. They only just stopped short of threatening to take my life.
'He was threatening very serious damage to me and he claimed to know where I lived.'
Last week Reeve, from Looe, Cornwall, pleaded guilty to five counts of communicating false information with intent and causing fear of violence.
He also admitted twice communicating false information that a bomb was in the ITV studios at Langage Science Park in Plymouth, Devon, and will be sentenced next month.
Plymouth Crown Court heard he sent emails 'of an extremely explicit sexual nature' with some specifically referring to Ms Bowater's pregnancy.
The court heard he was 'fragile' and lived with his parents and his threats were considered 'very real'.
Mrs Bowater, who is now a full time mother and lives in South Devon, said after the hearing: 'I am so pleased that this cowardly man who terrorised me, my family and my unborn children for so many years has been brought to justice.
'He was saying all sorts of unspeakable things that an unspeakable person would do to a woman.
'People ought to realise you can't do this to people. Maybe people go on the internet and think if they send emails or say things it doesn't affect people, but it does.
A police spokesman said: 'This should send out a stark message to those who think, for whatever reason, that they will not be caught if they choose to undertake this kind of reckless activity.'
Suspect Faces Cyberstalking Federal Charges For Indiana Incident
An Ohio man who used phony MySpace (dot) com pages to embarrass a Lake Station couple faces federal cyberstalking charges.
Thomas Slapnicker, 26, was arrested near Cleveland, Ohio for allegedly making threats against a victim in Lake Station and her partner, and using the social networking website MySpace to create Web pages posing as the couple, according to a federal indictment released this week.
The indictment says that after the woman obtained a court order prohibiting Slapnicker from contacting her, he then used MySpace and other sites to embarrass her and make her boyfriend appear to be a racist pedophile.
On one phony page, Slapnicker posted the victims' address and offered to meet strangers there for sex.
On a second page, he portrayed the second victim as a pedophile and a racist, again posting their address and inviting "those who disagreed with these claims to meet (the victim)" at their residence, the indictment states.
Slapnicker also allegedly made a series of threatening phone calls to the victims from Ohio, a violation of a restraining order.
Slapnicker's attorney, Roseann Ivanovich, could not be reached.
Authorities say he has been jailed since being arrested and will be transferred to Indiana for federal court hearings in Hammond.