'Call the Midwife' has been helping people with real-life issues.

Leonie Elliott

Leonie Elliott

The period drama show, which follows a group of midwives living in East End London in the 1950s, has touched on a number of different issues - including birth defects, young pregnancies and abusive relationships - since it hit screens in 2012 and, although the scenes can sometimes be hard to watch, the writer Heidi Thomas has revealed fans have been writing in to thank them for breaking taboos and educating.

Speaking to the Daily Star newspaper, Heidi said: "When we had a medical mystery storyline, The Cystic Fibrosis Trust had a 2,000 per cent increase in their traffic in the days after the show and more mums took their babies to the doctors for checks. l People have written to the actors saying we've broken a taboo and allowed them to speak about stillbirths, or being in a mum-and-baby home when they were younger. And a couple of series ago, a support worker persuaded social services to allow a couple with learning difficulties to share a home because of a story we'd told. I don't think you can put a price on having that sort of effect on people."

And Heidi received praise last year when she cast Leonie Elliott - who is known for her role in 'Black Mirror - as the show's first West Indian character.

She said at the time: "We'll be introducing our first West Indian young regular midwife to Nonnatus House in series seven. She's going to bring stories with her and a different cultural point of view and that's very exciting.

"My research is continually bringing up new things. One thing we're really looking forward to in series seven is my research has made me very aware of the contributions made by West Indian and Caribbean nurses to the NHS in the early 1960s. Elegant, funny and clever, Lucille is swift to settle in and bring a fresh new energy to life at Nonnatus House. Casting is currently underway and we look forward to introducing Lucille to our 10 million fans very soon."