The former Blind Date host wept when asked about the death of her premature baby Ellen in 1975.
Black's daughter was born when the TV star was only 27 weeks pregnant and died after two hours.
"It was awful. I could hear in the next room two women talking about their babies and I had none," said Black.
"You blame yourself and think, 'Maybe if I didn't work, maybe if I rested'. But I worked through my other pregnancies, so why should this be different?"
Black has three sons, Robert, Benjamin and Jack from her marriage to the late Bobby Willis.
The interview airs on ITV1 at 10pm on Saturday.