Call The Midwife will not have to end any time soon, its creator has said.
The first hit series was set in the late 1950s while the ninth instalment begins with Sir Winston Churchill’s funeral in 1965.
But the passing of time does not mean that the end is in sight for the drama, about nuns and midwives working in London’s East End.
Heidi Thomas told Radio Times magazine: “Call The Midwife has come a long way from the twin sets, pearls and dirndl skirts of series one. And the changes have not been confined to the wardrobe.
“All across Poplar, people’s lives have been transfigured by slum clearance, antibiotics, vaccinations, contraception, and gas and air in childbirth.
“Indeed, things are looking up so much that our fans have started fretting, asking, ‘How much longer can the show go on?’”
But she added: “They have no need to worry.”
The next series tells stories involving cancer, dementia, fistula, prostitution and homelessness.
The show will always be about “hope, generosity, kindness, and love,” Thomas said.
“Sister Julienne (Jenny Agutter) and her devoted team have more work to do than ever, because change is never instant, or complete, nor is it always welcome,” she said.
“In Poplar in 1965, the welfare state is flourishing, but family structures are breaking down.”
The BBC previously announced the drama, inspired by the memoirs of former nurse Jennifer Worth, will air until at least 2020.
Currently starring Helen George, Leonie Elliott, Stephen McGann and Jennifer Kirby, it first aired in 2012.
The full interview is in Radio Times magazine.