Nancy is busy with her continued support of on-the-run friend Mitzeee Minniver (Rachel Shenton) when she suddenly starts suffering agonising pains and has to be rushed to hospital.
As the anxious Osbornes wait for news, an emergency Caesarean is performed on Nancy and her baby boy is brought into the world - but whether he'll be okay remains to be seen.
Digital Spy recently caught up with Jessica Fox, who plays Nancy, to hear more about the storyline.
2012 is turning out to be a big year for Nancy. Are you enjoying all of the drama?
"Absolutely! When you're in a soap for a long time, you know that you're going to go through cycles of storylines. You'll be at the forefront of something for a while, and then you might be more of a supporting character with lighter stories.
"But it's really exciting when you know that you've got something big and dramatic coming up - you run up every day and look in the drawer to see if the next script is out. It's brilliant and I'm really lucky that I get to work so closely with both Ashley Taylor Dawson and Rachel Shenton, who I get on really well with."
Over the next few days, we'll see Nancy continuing to support Mitzeee. Does she have any doubts about whether she's doing the right thing?
"None at all! I think Nancy's attitude stems from everything that happened with her sister Becca when she was wrongly accused, sent to prison and ultimately murdered in jail. Because of that, she's really desperate to get this right for Mitzeee - to get her out and take Mercedes down!
"I think the thing with Nancy is that she's a bit like a dog with a bone. If she's decided that she's going to do something, it's very difficult to change her mind. All her focus at the moment is on getting Mitzeee free and clearing her name."
When Nancy and Mitzeee got to know each other in Hollyoaks Later two years ago, did you have any idea their friendship would become so strong?
"I didn't, no! They're such different people on the surface, but deep down Ann Minniver - Mitzeee's alter ego - is very moral, kind and caring and she's a very clever girl. I think those are all things that Nancy responds to and enjoys. Also, I think Mitzeee just makes Nancy laugh. Mitzeee can be a bit silly sometimes, and that makes Nancy smile."
What does Darren think about Nancy's antics?
"He's absolutely furious. Darren can't believe that Nancy is going against the law, is running around and getting stressed - especially while she's heavily pregnant. He urges her to put the baby first, but Nancy thinks he's just being silly and wants him to stop nagging her. Nancy thinks she knows best, as Nancy always does."
What goes through Nancy's mind when she suddenly experiences pains while spending time with Mitzeee?
"Well, she's been feeling slightly off for a couple of days - she's been a bit tired, dizzy and unwell. But she just thinks that's part of the pregnancy and she's got it into her head that now she's had the 20-week scan, everything is going to be fine.
"When Nancy does start getting pains in her stomach, to begin with she just ignores them. But in the end she realises they're getting more and more painful and she'll have to go to hospital. That's when the panic starts to set in."
Did you do any research into premature births?
"Yes, I did research it. Obviously there's a bit of artistic licence that goes into the scripts, to make things more dramatic or to let the story flow better. But I did do a lot of reading about premature birth and premature babies - all the things that can go wrong and all the things that can go right.
"Myself and one of the writers actually had a meeting at the Liverpool Women's Hospital. We spoke to one of the midwives who deals specifically with premature babies, which was really helpful."
Does Darren blame Nancy for putting the baby at risk with all her recent stress?
"He does indeed. Because the situation is so traumatic and scary, he doesn't want to let Nancy know that's how he feels. But being Darren, he can't quite hide it! Nancy is very scared about the baby and doesn't really pick up on the fact that Darren is behaving quite strangely at first."
If everything turns out well, what kind of a mother do you think Nancy will be?
"I imagine that she'll be a bit of a neurotic mother, particularly as the baby has arrived so early. I think she'd want to wrap him up in cotton wool and not let him out of her sight. But we'll have to wait and see what happens."
Would you like the Nancy and Mercedes feud to become a long-running one?
"I'd really like that. I think there's a bit of a bad girl in Nancy that has come out during this storyline. She's got more fire in her belly than maybe we'd realised, and I'd quite like to see her go head-to-head with Mercedes or somebody else.
"I always think Nancy is a bit of a moral compass for the show. She knows what's right and she's often the voice of that. I think that's a really good role for her, and it's quite an important one. I think it's quite good to have a strong, intelligent woman in the show."
On a less serious note, your hair has often changed during your time at Hollyoaks. Would you change it again?
"Absolutely - I just need to decide what I want it to be! That's one of my favourite things about being in a soap for a long time - I do get to change my image a lot.
"I always like to see the reaction, too. When my latest style came out as I'd cut it into a short bob, I got so many tweets from people - some negative, but mostly positive thankfully! When I figure out what I want to do with it next, I'd definitely change it again."
Will Nancy play any role in Esther's bullying story?
"I really hope so. I haven't done as yet, but she is part of Nancy's family in the Osbornes and I hope that they explore that, because they've already had some really lovely scenes together.
"I'd really like it if Esther were to confide in Nancy at some point, and for Nancy to take her seriously. I think whenever Esther has tried to speak out so far, it's been ignored, misconstrued or not taken seriously. I really want Nancy to be part of that, to believe Esther and help her. But I'd really like Esther to punch Maddie again as well!"
> Read the latest 'Hollyoaks' spoilers and news
Hollyoaks airs weeknights at 6.30pm on Channel 4, with first look screenings at 7pm on E4.