Helen Mirren has said she thinks a disturbing educational film she was forced to watch in school is the reason she decided not to have children as an adult.

Helen recalled recently that at around 13 or 14, the biology class at her all-girls school in Southend was bussed to a nearby boys’ school to watch a film of child birth: “[we were] just at that age when you’re just beginning to be self-conscious about your physicality and about boys and all that.”

The film showed the event in close-up and within 30 seconds, Helen claims two boys had fainted: “And that’s all you see and these are 13-year-old boys and girls who can’t look at each other anyway, and it’s bloody and it’s disgusting.”

“I think in deep proper psychological terms I was traumatised. I haven’t had children and now I can’t look at anything to do with childbirth. It absolutely disgusts me.”

But she added that her experience with her own mum might have compounded her desire not have children herself: “She was horrible, she could say very cruel things and it was difficult at home. She wasn’t born to be a mother.”

“She could be mean. She’d say just very, very hurtful, bitchy things.”

“It was impossible for us ever to take a boyfriend home because they were just never good enough.”

“I’ve sort of wiped it from my memory actually. Now the mother that I remember is the mother that I knew after the death of my father and that I loved very, very much and I spent a lot of time with.”