In What to Expect When You're Expecting, former Sports Illustrated model Brooklyn Decker plays Skyler - the much-younger wife of racing legend Ramsey Cooper (Dennis Quaid) - who are over-the-moon to find out they're expecting.

Decker talks wearing the prosthetic baby bump, working with Dennis Quaid and making the transition from model to actress.

Click here to read more about the film and watch the trailer.

Talk about your experience with the fake mummy-belly, please.

What’s funny is that few of the cast members had gone through pregnancy.  Well, Jennifer (Lopez), but other than her, none of the other girls had gone through the process of giving birth. It’s surprising how you feel when you have the prosthetic on.  You become maternal.  It’s weird. As a woman, all of a sudden, you have this instinct that comes out.  I found myself protecting the belly as I was walking around – and its rubber. I’m holding my lower back!  People would hit it and I’d be very protective of it, like, ‘No, no. don’t touch my belly.’ I was very careful with it.  It’s funny. I think as a female, you kind of naturally fall into it. Your maternal instincts come out, even if it is a prosthetic.   

How about clothing. Was it difficult to wear heels?

I was forced to. (laughing) But absolutely. You’re front heavy so you find yourself waddling a little. That was something we all had to practice quite a bit. We had a midwife on set that would teach us how to properly waddle for our pregnancy, which made wearing heels really interesting. But it came quite naturally. 

Do you think there are more opportunities for former models these days?

I don’t know. 

Maybe more respect and a greater chance to make it as an actress?

No. I met with a lot of resistance – which is quite fair, to be honest.  I understand the business that I came from and I think there’s a process that I have to go through of proving myself. I’m doing that. I have a lot to learn.  I’m still very new at this so that’s okay with me. The work put into proving myself; that’s exciting. I don’t think it’s easier than it used to be, to make the transition. I love that the door is opening up a little bit.  Rosie in Transformers and myself, but I think the work is still kind of cut out for us to prove ourselves.

You’re married and have been for two years. (To tennis star, Andy Roddick). Are you planning a family?

I love babies. I love children.  I can’t wait for the day to come to be a mother. I don’t see it coming anytime soon. For now, playing a pregnant person on set is enough for me.  I would definitely love to have a family one day, but I feel like I have some time.

This is the second time you play the role of a May/December marriage. What is your take on the older man/younger wife phenomenon?

It’s a common theme for me to play that girl in movies, isn’t it? (laughs) What I loved about my character is that you never question her motives. They live life very easily and nothing has ever been difficult for them. They are just genuinely in love with each other.  I don’t think there is an age to love. The relationship in the film is incredibly over the top and ridiculous, but it’s quite sweet.

Did you discuss the experience with Dennis Quaid, who plays your husband – as he has a much younger wife?

He does. We decided we just wanted to have fun.  There’s some sad storylines in the film. It taps into all aspects of pregnancy, good, sad and tragic. Ours had to be over-the-top fun.  Heightened. Nothing about our scenes were grounded. We thought the more gross, and in your face, the better – so we just went for it. We were silly and I enjoyed it because I got to be ridiculous.

About the film:

Over the moon about starting a family, TV fitness guru Jules (Cameron Diaz) and dance show star Evan (Matthew Morrison) find that their high-octane celebrity lives don't stand a chance against the surprise demands of pregnancy.

Baby-crazy author and advocate Wendy (Elizabeth Banks) gets a taste of her own militant mommy advice when pregnancy hormones ravage her body; while Wendy's husband, Gary (Ben Falcone), struggles not to be outdone by his competitive alpha-Dad, who's expecting twins with his much younger trophy wife, Skyler (Brooklyn Decker).

Photographer Holly (Jennifer Lopez) is prepared to travel the globe to adopt a child, but her husband Alex (Rodrigo Santoro) isn't so sure, and tries to quiet his panic by attending a "dudes" support group, where new fathers get to tell it like it really is.

And rival food truck chefs Rosie (Anna Kendrick) and Marco (Chace Crawford)'s surprise hook-up results in an unexpected quandary: what to do when your first child comes before your first date?

Watch the trailer below: