Discovering she had a twin who died at birth has made singer Connie Fisher fearful of having a baby.
The West End star from Barry said she only found out she had been born a twin after an off-the-cuff remark from her grandmother when she was 10.
She made the revelation when filming BBC documentary Baby Love.
The 34-year-old said people asked her on an almost weekly basis if she planned to have babies with her husband of seven years but it was a dilemma.
"Some people seem to instinctively know the answer to this question but I didn't," she said.
"If you're not sure that you wanted it it could be a whole life sentence."
The programme sees Fisher visit a Cardiff clinic for fertility testing and meet women with different perspectives of motherhood.
She meets a 45-year-old who has suffered five miscarriages and been unable to have a baby, a lesbian couple who conceived using donor sperm, a woman who suffered postnatal psychosis and a friend who at 73 is happy with her decision to remain childless.
She also meets hypnotist Andrea who after eight years of unsuccessful fertility treatment conceived her daughters using donor eggs.
Andrea hypnotises Fisher to try and help her unlock the reason for her quandary over becoming a mother.
While hypnotised, Fisher recalled her grandmother praising her Scrabble playing by saying: "Justin would be really proud of you".
She became upset and said: "And I knew who Justin was, I just knew. He's my brother. She didn't even have to say. And I didn't know and I was 10 and no-one had told me."
Her mother gives her more details about what happened: "I had a problem free pregnancy… I sailed through it. The delivery was where I encountered a few problems."
She recalled waking up following a Caesarean: "I remember waking up the following morning and the face of the doctor was staring into mine and before he could say anything I said 'it's ok, he's gone' - I told him what he was about to tell me... and I just knew.
"I came out for the day and left you in hospital and went to Justin's cremation."
Fisher tells her: "I kind of knew I was a twin before you told me... knowing your story and my story there's a fear of loss."
Her mother tells her she should not be afraid of becoming a mother: "I was unfortunate to lose a child but that's a rare occurrence."
Connie Fisher: Baby Love is on BBC One on Thursday 18 January at 20:00 GMT.