Fans of Call the Midwife might want to prepare to bust out some tissues because the next season is about to have heart-wrenching storylines.

'Call The Midwife' Christmas Episode Chatter

On Saturday, Radio Times posted the details from series advisor Terri Coates who mentioned that the tragic moments can affect her as well as others who are part of the series. One storyline in particular involves a woman pregnant with twins, but loses one of them while she's still expecting. Even though this story is fictional, Coates made it clear that it's still a frightening thought.

"It's a sad storyline. Just thinking about and going through the story is actually quite hard because you're thinking about the loss of a child and how it will affect that family," the advisor said. "It's dealt with incredibly sensitive and people are given the chance to talk about it. It's make-believe but it can affect people very deeply."

Storyline For 'Call The Midwife' Season 4 Is 'Terribly Upsetting'

Coates also talked about how a tragic story involving the loss of a child is added into the show with a careful procedure.

"Whenever anything like that happens it will trigger recognition and memory of lost babies," she said. "It's never treated lightly and it's never done without a lot of research into how it would affect not just the mother but the father, the family, the midwives, the whole community."

Call the Midwife Season 4 is expected to air in the United States this spring on PBS.