Rachel is helping out with the preparations for the village nativity when she suddenly starts experiencing contractions, which leave her terrified as she isn't due to give birth for months.
After Rachel is rushed to hospital, her baby son Archie arrives safely but isn't out of the woods yet. To make matters worse, neither mum nor baby can rely on proper support from Jai Sharma (Chris Bisson), who is still hiding the fact that he is the child's father.
Digital Spy recently caught up with Gemma Oaten, who plays Rachel, to hear about the big scenes in store.
How did you feel about taking on a premature birth storyline?
"I knew the storyline was coming up for a little while, because sometimes the producers give you a heads-up if something really big is on the way. Then when the scripts came out, I was blown away. I've only been out of drama school for two years and I never dreamed that I'd be getting an opportunity like this. As actors we love to play all sorts of different emotions, so I feel very lucky to be given this chance.
"I was very scared leading up to filming the episodes, because I wanted to do a good job. But the director Peter Rose was phenomenal and it was great that Alicya Eyo and James Hooton, who play Ruby and Sam, were there for the hospital scenes as they're two of my best friends. I felt surrounded by a fantastic comfort blanket."
Did you do any research into premature birth?
"I did quite a bit of research online. One thing I found out was that the timescale is so short from experiencing the actual contractions to having the baby. So you'll see that Rachel goes into hospital and the baby is born within the hour.
"I also looked into the emotions of what women go through. One thing I found is that a lot of women who give birth prematurely often feel guilty and wonder if they did anything wrong. But then obviously they're ecstatic that the baby is there, so it's a real mix of emotions for a new mum. It's quite a scary position, so I did a lot of reading. I just hope that I've done it justice."
Did you film these big scenes before or after the live episode?
"All of this kicked off for me after the live episode. I tried to keep it quite quiet because fans of Emmerdale who follow us on Twitter are very quick off the mark and very clever! They read into tweets and often figure out what we're filming, so I tried not to speak too much about it and just kept focused.
"It's quite satisfying that nobody really got hold of the storyline until the spoilers were officially released. It was quite an intense period for me, because obviously we'd just done the live episode and then I had these big scenes to film. There's also a big aftermath with the baby in hospital, and then I'm still very busy on set at the moment as well."
When Rachel goes into labour, is there a part of her that wishes Jai would just be honest with everyone and support her?
"I do think Rachel wants the secret to come out now. I know a lot of people think that Rachel should be petrified of Charity, but actually she's finding an inner strength and her main concern is making sure that her baby is alright. She just wants her little boy to survive and she couldn't care less if Charity finds out, because she wants to have the dad there.
"Obviously that's not the situation, but instead Sam is becoming more involved and that makes Rachel feel like she's not alone. She's finding a lot of strength from Sam."
What do you make of Rachel's choice of baby name - Archie?
"I love the name! It's really weird, but my sister gave birth in May to a beautiful little girl called Rosie, but if the baby had been a boy, she'd chosen the name Archie. I think Archie Breckle has got a good ring to it!
"I just can't wait to meet the real baby, because obviously we've been filming with a model so far. The model has been absolutely amazing, by the way - the props department did a brilliant job. But I can't wait to see the real baby!"
There comes a point in the storyline where Rachel bans Jai from seeing Archie. Why does she make that decision?
"That was never going to happen in Rachel's mind, but it's actually Rishi who comes round after the baby is born and he says that Rachel needs to encourage Jai to back off. Rishi starts implying that the business is at stake and Jai's marriage is at stake too, so he's putting a lot of pressure on Rachel.
"Rachel feels like she has to tell Jai to back off following Rishi's warnings. Rachel wants Jai to see the baby, but it's Rishi who puts a spanner in the works and he makes things a lot worse."
Could Rachel and Sam's friendship develop into something more?
"I don't know! In all honesty, I still haven't seen any scripts where that happens, but I know that they are getting close. Ruby thinks that Sam is falling for Rachel, but she encourages him to back off because Rachel is not ready for this. In Sam's head, he'd never even entertained the idea, but when Ruby mentions it, things start to change slightly for him!
"It's the same for Rachel. She doesn't see Sam in a romantic way, but when someone mentions that they could be more than just friends, she wonders if they're right.
"All I can say is that I'm really happy that Sam and Rachel are getting close again, because I adore James and we get on so well both on set and off. It's so nice to be working closely with one of my best friends, so watch this space for some sweet and touching scenes. Personally speaking, I would like things to go further because I think they'd make a brilliant pairing."
Is the truth about Jai being the father going to be revealed soon, or is there still a long way to go?
"I think there's a lot of longevity in it. One of the things we've discussed is that if the secret was blown too soon, people wouldn't invest as much in it. People need to see Archie maybe growing up a little bit before the truth comes out, because then the impact will be bigger. And if Rachel and Sam got together further down the line, what would that mean when the big secret is revealed?
"I think they're going to try to keep this one a secret for a little bit longer yet! I know the viewers are keen for it to be revealed, but I know when the scenes do eventually come around, it'll be amazing. Myself and Emma love going up against each other as Rachel and Charity. Although it's terrifying - I come away with heart palpitations!"
Will there be any happiness for Rachel at Christmas?
"I think there's a little glimmer of joy for Rachel on Christmas Day. I don't want to give away too much, but there might be a little touch that will make her Christmas."
Will motherhood change Rachel?
"It's really funny, because I've felt that Rachel lost some of her feistiness when the pregnancy was first revealed. Her head was all over the place and she became a bit of a pushover, I think! But since I've been filming the post-birth scenes, I can see a real strength coming back into her. I think motherhood is making her start to realise that she is an independent young woman and she can get through this. She's holding her own again.
"Rachel has always had a protective streak in her - remember that when she first came to Emmerdale, it was because she was protecting her little niece Amelia. So I think motherhood is going to be a fantastic thing for Rachel, and it's great for Sam to be involved as well. Sam has been through the same thing - when he lost Alice, he had to bring up a little boy on his own. He might come across as a simple mind but he can definitely hold his own."
Finally, there's lots of speculation at the moment about another Emmerdale death this Christmas. Are you sad to see another colleague leave the show?
"I am. You become very close to your co-stars, whether you film with them a lot or not. I still miss Tom Lister every day and I was only on the show for 16 months with him. I'm also very sad to see this next person go, as they will be missed. But I also know that they're going to go on to a very successful career. The person leaving is a really good and talented person.
"There seems to be a massive change at Emmerdale at the minute - it's not a bad thing and everybody's just trying to embrace it. Kate Oates is going to be taking over as producer in January and there's a lot of new faces in the corridors who I think the viewers are going to love meeting. They're such lovely people and it's an exciting time."
> 'Emmerdale' Chris Bisson talks Jai baby nightmare - interview
> Read the latest 'Emmerdale' spoilers and news
Emmerdale airs weeknights at 7pm on ITV1, with an extra episode at 8pm on Thursdays. Get the Inside Soap magazine on your iPhone or iPad