The BBC previously confirmed the hit period drama would be getting a prequel series, set to air this Christmas, and a film.
It is understood that the Call the Midwife prequel will be set in Poplar during World War II and will be created by Thomas.
Details on the film are still being kept tightly wrapped, but the BBC have confirmed it will be set “overseas in 1972 and feature iconic characters from the existing TV show.”
Ahead of filming for the prequel, Thomas has shared which characters from the main show will appear in the new series.
Call the Midwife creator confirms characters starring in prequel
Speaking to Radio Times at the magazine’s 2026 Covers Party, Thomas shared that younger versions of Sister Julienne (Jenny Agutter) and Sister Evangelina (Pam Ferris) will star in the prequel.
Sister Evangelina was in five series of Call the Midwife; however, the character died due to complications following a stroke.
Thomas also shared that the returning Sisters will be joined by three new young midwives who are all “relatively new to the East End.”
Talking to Radio Times about the new prequel series, the Call the Midwife creator said: “I think the interesting thing for me is it’s a world where women are not in charge when war breaks out, but very rapidly, they are in charge of everything because the men are called away, either to Home Front-based war work or they go overseas.”
Adding: “So you’ll see a lot of women coming into their own… it’s a programme that is going to be about strong women above all else.”
The news comes after star of Call the Midwife, Judy Parfitt who plays Sister Monica Joan, confirmed there will be a break from the main show when the current series ends.
Speaking to Radio Times , Parfitt said: “This time of year, you thank God you’re nearly finished because you’re so tired.
“From about the beginning of March, you start thinking how lovely it’ll be to see everyone and start working again. Then it’s April and I usually look forward to April.
“So, for it not to be there really shakes me a bit. This company has been through so much together that we are a family. It’ll be hard for all of us.”
Parfitt, 90, has been a part of the Call the Midwife cast since the show began back in 2012, and said she has “loved” playing Sister Monica Joan.