Call the Midwife is often praised for shining a light on important but often overlooked issues regarding women's health and motherhood - and Sunday night's instalment is set to continue this with a storyline about the vital importance of sex education in schools.
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The episode will see nurse Nancy and Sister Frances pay a visit to a local primary school to give a talk on the facts of life after it's discovered that some of the female pupils have started their periods early.
Sitting down with HELLO!, actresses Megan Cusack and Ella Bruccoleri, who star as the two Nonnatus House nurses, revealed that they felt a "massive responsibility" after being chosen to deliver the storyline which will resonate with audiences both old and young.
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"The whole point in the episode is that we're enlisted to do this is because some girls have started their periods really young before anyone has had that chat with them," Ella explained.
"It's really traumatising to be that young and suddenly have blood coming out of you and not know what's going on," she added while Megan said: "You'd think you were dying, wouldn't you?"
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The two revealed that their own experiences of learning about periods and sex in school in the early 2000s was far from ideal. "Growing up in Ireland, there wasn't much [sex education]," Megan said, and Ella admitted that at her Catholic school it wasn't part of the curriculum.
© Photo: BBCMegan Cusack's nurse Nancy has been involved in several heavy storylines
"People still think it's a dirty thing," she stressed, explaining that not much has changed since the 1960s as periods remain a taboo subject in society today even though it's the "most natural thing in the world".
The actress continued: "When it's something that's really unexplored as well and there's suddenly loads of people who feel seen for the first time if that's your storyline, I think it can be a massive responsibility to suddenly feel that you have to speak about that in a way that is articulate. I find it quite hard sometimes."
© Photo: BBCElla Bruccoleri stars as Sister Frances on the show
"You do take it home and feel the weight of it," Megan said before revealing that she was left emotional earlier this year after viewers reached out to her regarding one of her other sensitive storylines. In season ten, viewers learnt that Nancy has a daughter who was given up for adoption as she was 16 and unmarried when she fell pregnant.
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"I've had a lot of people message me because they were adopted and I feel very honoured that people confide these stories in me. I think it's very beautiful but when you're in it, you sometimes don't think about it."
"The episode where I told Colette I was her mum I just had this influx of people messaging me. It was really sweet. One of them made me cry."
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