It wouldn’t be New Year without a fresh series of Call the Midwife, the BBC smash about cycling midwives and nuns in Fifties London inspired by the memoirs of Jennifer Worth. Indeed, this is series six, it’s now 1962 and the midwives are facing different challenges, as its award-winning writer, creator and executive producer Heidi Thomas explains.

“We used all the best stories from the Worth trilogy in the first series, because we didn’t think it would be recommissioned for a second series, let alone a sixth.” But it was, and it has, and to get round the fact that Worth didn’t write a 20-part saga, Thomas decided to move the goal posts, so the babies turn up amid a wider social picture.

“We had to source more original material, and one way of doing that was to look at social history and GP medicine in those days. Because, as one of our professional midwives on set says, there are only so many ways a baby can make its way out into the world. I didn’t want to make a series predicated on the way women’s lives are endangered through giving birth. It would be very easy to make every birth a crisis, but most births are not. Some births are complicated, but certainly not twice a week.” 

Heidi Thomas is one of Britain’s most successful, prolific and versatile screenwriters. That she comes across as a cosy, smiley fifty-something lady in pearls and a silk scarf, who might well enjoy birdwatching and jam making at her home in a Cambridge village, is to her credit.

She probably does enjoy all of the above, but that element exists alongside ferocious drive, abundant talent and an awesomely high level of organisation. Indeed, her husband, the actor Stephen McGann who plays the deliciously proper Dr Turner in the series, put his own career on hold so that Thomas could fulfil her own.

“Call the Midwife was originally greenlit at the same time as the second series of Upstairs Downstairs, which I was also writing,” says Thomas, pouring a cup of tea and declining the offer of biscuits, sandwiches and scones (“I don’t think so, post New Year”).

 

Heidi Thomas's husband, Stephen McGann, plays Dr Turner in the show

“Our son Dominic was 12, and it was clear I would be unable to manage my workload if Stephen was off acting in the West End. But we are a feminist household, and Stephen rather gallantly agreed to take a career break so I could major on my writing. People ask me how I manage and I say, ‘Because my husband took two years out of his own career’, although he did do a science degree along the way.”

Indeed, Call the Midwife, or CTM as Thomas calls it, has a very similar style to the woman who now creates it; it may seem like a warm bath, but dip your toe in, and you will find feminist zeal beneath the fragrant bubbles.

This is a show where interesting, complex roles are continually given to women. Men don’t get a look in, even the rugged Dr Turner. It’s not surprising that actresses of the calibre of Jenny Agutter, who has starred in every series as Sister Julienne, or Sinead Cusack, in this year’s Christmas special, or indeed Dame Harriet Walter – in this series as the daunting Sister Ursula – queue up to be included.

 

“We are well known for creating strong roles for women and showcasing the interesting experiences that women have and have had,” says Thomas. “So we get expressions of interest from very senior actresses.”

One familiar name who will not be appearing, however, is Miranda Hart, despite press announcements that she would reprise her role as the chaotic midwife Chummy. “We were thrilled when Miranda approached us, and I storylined the series for her, but at relatively short notice she had to withdraw.” How short? Thomas smiles, friendly but firm. “I can’t say, but it was short. We were hopeful right up to the end that we could make it work, but we couldn’t.”

Miranda Hart as Chummy

What did you do? “I just rewrote the series without Miranda in it, which was sad because we would have loved having her in it.” Impressive. Thomas pours more Assam tea as if to indicate the subject is closed. “She is part of the CTM family. But [this time] it wasn’t meant to be.”

Another thing CTM isn’t meant to be is a soap opera. “People say, ‘What is the secret?’, and I say, ‘Gradual, persistent change.’ In some long- running shows there is a pressure to keep characters going on and on with new stories, but that does not replicate life. My mantra is, ‘We are not a soap. We are a medical drama.’”

Bringing social medicine into the mix provided a huge source. “The history of our country is written in prescriptions, diagnoses and the development of sanitation. Medical development, whether X-rays or the Pill, pushes us on a little bit.”

The new series covers a vast array of social issues, including domestic violence, parenting as a disabled person and the working conditions for dockers. Most startling is the inclusion of female genital mutilation (FGM), which Thomas chooses to refer to in less charged terminology.

“I was first interested in female circumcision after a radiologist friend told me about working in the United Arab Emirates and coming across women with very mutilated anatomies. It was in my mind as a potential storyline, because it causes terrible complications in pregnancy as well as carrying huge and very complex cultural weight. However, it had to go on ice because in the Fifties, there weren’t appropriate cultural communities in the East End.”

But by 1962, there were. “The Somali community was just establishing a foothold, so it was likely that there would have been women who had experienced a particular type of incision where the clitoris and the external labia are removed and a very plain line is created with a very small vaginal opening.

 

“It happens at quite a young age. Pregnancy is possible, and of course fertility is very highly prized in those societies so women would want to become pregnant. They would be dealt with by a traditional caregiver at birth, where they would be reopened. I thought this would be a fascinating story, as it would be the first time our midwives would have seen this process. It would provide a very interesting crunch point between two cultures, and of course it is now a very hot topic, quite rightly.”

How do you cover such a subject in a cosy show such as CTM? Keeping true to the politics of the day and focusing on the medical aspect was Thomas’s approach. “You always have to look at things from two points of view, one from the Western nurse who has never seen this sort of thing before, and one from the woman who accepts it as it is part of her culture.

“It is very important not to look at it just from the white point of view. And in 1961, young unmarried midwives might not perhaps be as militant about the importance of the clitoris as we might be today.”

It seems that in this episode (not released to Radio Times), FGM is dealt with as a fascinating medical aberration, not a grim abuse. “The midwives do very much deal with it in terms of medical caregiving, rather than sexual deprivation,” she says. “In the current climate when people discuss female circumcision there is an element of concern about women’s autonomy and sexual experience, quite rightly, but you do have to be careful not to impose a modern mindset on the attitude of either the white characters or the Somalian women in that part of the story.”

Doesn’t she feel a duty to represent FGM more critically? “We always have to observe historic boundaries. We take a very clear-eyed view of different cultures and how they operate in relationship to one another and the medical dangers of such a procedure. We are a medical drama, not a moral drama. We are not judging this woman. We are stating the facts of what it is like giving birth when you have had your sexual organs completely modified in a way that is not in the woman’s best physical interests.”

Modified? “It’s not OK,” says Thomas. “In actual fact there is one small medical detail on screen which the BBC did question, in terms of taste and decency. And we said very firmly if you erase that small visual moment, it is underplaying the horror and the pain of the situation. But we wanted to look at the issue from several angles because that is what we always do.” It will be interesting to see how this is received, but there is no question that Thomas knows her creation and how she wants it to be.

One thing is for sure and that is we are not about to see CTM: The Movie. “It has never been discussed. The TV series is in such rude good health, and we have been commissioned to make three further series.”

How about if Dr Turner is tempted away from the GP surgery by Hollywood? “I suppose technically I am his boss, but I have never needed to wield that particular stick,” says Thomas. “Which isn’t to say that it won’t happen. If he was offered a role in Pirates of the Caribbean 7? The big stick would come out then.”

Call the Midwife is on BBC1 tonight at 8pm