There's a new pregnancy trend that has swept over Hollywood. It's called the "No Bump" pregnancy. As you may have guessed by the name of the movement, it's when celebrities attempt to hide their baby belly for as long as possible. The negative element in this trend is that some women are taking it a bit too far by resorting to extreme dieting to hide their growing belly. Obviously, this type of dieting is in no way healthy for either mom or baby.

Though in Hollywood, it can be difficult to tell who is dieting like crazy, who is a pro at pregnancy fashion, and who is simply carrying her baby discretely. So, we've compiled a list of celebrities who had notoriously small baby bumps to let you decide for yourself.

Most of them were able to hide their pregnancy for at least five months and some even hid it for longer than that. The question we should all be asking is why would any expecting mother feel it necessary to do this?

Well, while most women are excited to start showing, celebrities make a living from the way that they look. If their looks are altered because of weight gain or loss due to any reason, this could mean chunks of money taken from their pay day. So, let's see what you think about these 15 women who barely changed during their pregnancy.

15 Marion Cotillard’s Showing She’s Not Showing

A lot of people know the face of Marion Cotillard because of the Brad Pitt/Angelina Jolie divorce scandal. As it goes, Jolie hired a private detective to tail Pitt towards the end of their crumbling marriage. And she didn't like what she saw. Mostly, what she saw was chemistry between her husband and this French actress. The only thing was that the directors of Allied saw the same chemistry...on set, so the evidence itself could be problematic .

Whether Cotillard played any part in the downfall of Brangelina remains unproven. What can be proven is simply that Cotillard was pregnant with long-time partner Guillaume Canet's child in the picture. As long-waisted as she is, it seems natural for her not to be showing that much. And, clearly she's not attempting to hide anything by wearing such comfy pink pants on her day running errands in Paris, France.

14 The Duchess Is Always Slender And Elegant

Although the Duchess of Cambridge is not from Hollywood, she's still one of the most recognizable faces in the media. And she is ALL over the media. That tends to happen when you marry the future King of England. Kate Middleton is also known for her impeccable style. Pregnant or not, she looks effortlessly flawless time after time.

One thing thing about this royal family member is that she naturally has a very slim and slender figure. Actually, she's much like her late mother-in-law Princess Diana. Because of this slim figure, it takes her a long time to start showing her baby belly. The thing about the Duchess is that she's not shy with her figure, so we know she's not on the "No Bump" train. Remember, she's one of the only celebrities who proudly displayed her post-baby bump upon exiting the hospital after giving birth. Clearly, she's okay with her bump.

13 Cheryl’s Minuscule Bump

X Factor judge and singer Geordie Cheryl Cole (stage name Cheryl) admitted to hating being pregnant. Although she is fairly quiet about the details of her pregnancy, she's spoken about it being incredibly challenging. Her partner Liam Payne has expressed his concerns, as well. During her pregnancy, in fact, she made an executive decision to back out of the limelight. Having been front and center for the better part of 14 years, she claims she needed the well-deserved break to focus on motherhood.

Although we're not sure exactly what difficulties Cheryl experienced, it's likely that morning sickness plagued her something awful. The few pregnancy pictures paparazzi managed to shoot were of a very tiny and very fatigued-looking Cheryl. We're speculating, but most mamas are more than familiar with that look. Usually it means the toilet has become your BFF. When women experience extreme physical symptoms like this, it can be hard for them to gain weight.

12 Jessica Alba And Her Fit Pregnancy

Jessica Alba is well-known for being the beautiful girl next door. She's the one woman that many other women want to look like and many guys want to be with. Here's the thing about Jessica Alba - there's one of her. Plus, she's already taken by hunk Cash Warren and they have a family of three kiddos.

As you might already know, Alba is incredibly health conscious and tends to sway on the side of organic and authentic when it comes to what she puts in her body. This mindset was evident throughout her pregnancies, too. Not only was she healthy during her pregnancies, but she was glowing and among the most fit moms out there. Although she's a tiny thing, her pregnancies didn't ever overtake her body like pregnancy is known to do. At least in Alba's case, her focus on health and fitness paid off big time.

11 Blake Lively The Bombshell

Whether you're a huge Blake Lively fan or not, it's undeniable that the woman has red carpet class. She can make a splash whether she's dressing a baby bump or not. Actually, her and her actor husband Ryan Reynolds are a class act together. Cute and funny! One thing about Lively is that she didn't change much during her two pregnancies. Although she is a late-shower, she does carry low towards the end of term which tends to give her baby belly a different look.

Lively has the reputation for being a "foodie and a cook," so she's definitely not one of those celebrities skimping out on meals. Especially not during pregnancy. More than anything, she appears to be a golden goddess channeling the sun-kissed look of a younger Goldie Hawn. And, this portrayal doesn't change during her pregnancies. She's just got that "it" factor.

10 Sam Faiers At Six Months Beauty

Sam Faiers is the younger sister of Billie Faiers. For those of you who are as familiar with this family, Sam was an member of the show The Only Way Is Essex or TOWIE. She was diagnosed with Crohn's disease in 2014. In 2015, she gave birth to a baby boy with boyfriend Paul Knightley. In 2017, the two also had a baby girl.

Although Sam undoubtedly has a naturally slim figure, she was barely showing here at six months pregnant. Some might say that the struggles with Crohn's disease was the cause of her barely there baby bump. Rumors fly that she has had a negative relationship with food as she's experienced trouble "keeping it down" in the past. In addition to her possible eating disorder, she's an avid fitness and health guru. And no, this isn't a compilation picture of Sam's pregnancies (she only has two kids). She just really likes selfies...and that dress.

9 Olivia Wilde Kept The Cuteness Coming

Olivia Wilde and Jason Sudeikis are proud parents of two children together, a son and new baby daughter. Pictured here is Olivia Wilde during her second pregnancy. As you can see, she's not showing very much, but she is keeping it as real as it gets in her comfy outfit. Throughout her entire pregnancy, Wilde didn't tone down her style at all. In fact, she upped the cuteness factor all around.

At the Friars Club Icon Award, she wore a gorgeous and flowing red gown. Even being three weeks away from delivering, she still really didn't appear to be donning that notorious basket ball belly that so many expecting moms do. Rather, she was just excited to have successfully not given birth onstage.

8 Sarah Stage Six-Pack Mom

If you're like most people then there's a good chance you felt the waves that this fitness guru made by displaying her six-pack during her pregnancy. Yes, you read that right - during. Going into pregnancy in the best shape of her life, she wasn't surrendering any of her love for fitness to baby weight. Unlike most women, fitness was at the heart of her pregnancy.

As you can see from the picture, she's not showing much and obviously very much in shape. Her approach to pregnancy caused a huge stir among many women. But, she continued on her mission to prove that fitness doesn't have to take a backseat to pregnancy. In fact, she is now offering a post pregnancy snapback guide on her website as a way for other women to maintain a physique like hers. What do you think?

7 Irina Shayk Walked The Runway

The face of Irina Shayk probably looks familiar to you not only because she's a famous model, but she is also the partner of actor Bradley Cooper. The two welcomed their first child together last year March 2017. This Russian born model was the cover model for the 2011 Sports Illustrated Swimsuit Edition. On more than one international "sexiest woman alive" list, she was listed alongside other beauties.

This picture is of her participating in the Victoria's Secret Fashion Show at the Grand Palais in Paris, France. No one knew she was pregnant, but she shared the news after the show. In revealing lingerie, she was able to crush this catwalk with ease. Being her first child, her belly was probably a little more stubborn to curve out at that point even though she was already in her second trimester. She was ecstatic about being a mom, so her belly took on a life of its own later in pregnancy.

6 Alessandra Ambrosio Goes Unnoticed

Another famous Victoria's Secret model Alessandra Ambrosio stormed the VS runway early in her pregnancy. Ambrosio was two months pregnant for this particular show, but like her co-model Irina Shayk, she didn't tell anyone. In fact, she was actually freaking out a little before the show. She told her booker that she didn't think she was going to be able to do the show. She'd already gained a few pounds and was unsure whether she'd fit into the clothes or not. But, they kept quiet.

She made a good choice in cutting out all sugars from her diet to prepare for the catwalk. Instead, she gave her body healthy foods and focused her fitness routine on her glutes, arms, and back rather than her belly. Luckily, she didn't experience any nausea in the process. She ended up wowing at the show and shared her news after it was over.

5 Katherine Heigl Is Barely There

Katherine Heigl was most definitely in the business of making money while on set of CBS drama Doubt. She is nearly five months pregnant here. Her due date was January and these photos were taken in Los Angeles in August. Now, Heigl is a first-time mother so naturally her baby belly isn't going to protrude as quickly as second-time moms.

Her and her country crooner husband Josh Kelley have been married since 2007. The couple are already parents to two other adopted children whom they adopted in infancy. So, this isn't exactly their first go-around with babies, but it is with pregnancy. Though, Heigl is not letting that slow down her career at all. She's cleverly being fashion forward with her pregnancy style.

4 Halle Berry’s Itty Bitty Bump

If this woman's gorgeousness doesn't blow you away without a baby bump then wait until you see her pregnant. Halle Berry is beautiful! And, really it's just because of her down-to-earth approach on pregnancy. In a slinky dress, Berry is attempting to hide absolutely nothing. It's actually her daughter trying to hide behind her mom from the annoying paparazzi rather than Berry trying to hide anything.

She does have a cute little bump while appearing to be fit and trim for this pregnancy. Now, this is early on. Berry's baby grew in leaps and bounds during the last few months. Naturally, mom did, too. Still, she was a brilliant site to behold and was as radiant as ever.

3 Billie Faiers Goes “No Bump”

Reality star Billie Faiers is most well-known for being a member of The Only Way Is Essex or TOWIE. This English actress has also been a part of her sister's (Sam Faiers) show The Mummy Dairies and directs a fashion company called Minnies Boutique, as well. Billie was a much-loved member of TOWIE. It's said that she was a natural on camera from day one.

In this selfie, she's actually 20 weeks pregnant. As you can see, she's not exactly letting it all hang out. Expected to live and dress like a fashion guru, it suggests that Billie feels the pressure to remain especially fashionable with her body by following the "No Bump" trend. In her defense, she did expand to accommodate her baby towards the end of the pregnancy. At that point, there was no choice to go "No Bump" or not

2 Emma McVey’s Slim Figure

If you can't tell or if you didn't already know, Emma McVey is a model making her living by modeling lingerie. Actually, she's an English born reality star who was feature in the 13th season of The Only Way Is Essex or TOWIE when she dated a co-star Mario. After they broke up, she began a whirlwind romance with Geordie Shore's Gaz Beadle.

The two announced that they were pregnant after breaking up and getting back together. McVey gave birth to their daughter this past January. Do you see the picture featured? Well, that's as big as this mother grew. For one reason or another, we did not see a big belly on this lingerie model.

Some would like to shout out that she was starving herself for her career. The only thing is that this size is not at all impossible by any means. Her baby was sitting deep in her pelvis and apparently didn't want to make a huge appearance. Still, her size caused a huge fuss in the media.

1 Kristin Cavallari’s On The Small Side

Kristin Cavallari is another Hollywood beauty that tends to fly under the radar drama-wise (at least now), but frequently makes a fashion statement. She's one of those steady celebs who keeps delivering great, everyday fashion to us. She became famous on the show Laguna Beach and The Hills when she was very young. Often teaming with one of the Kardashian sisters, Cavallari's face is no stranger to the paparazzi.

She has two kids with husband Jay Cutler (Chicago's quarterback). Claiming to have devoured sugar and carbs for energy during her first pregnancy, Cavallari approached her second one much differently. And, it showed! Not only did she appear healthier, but she didn't appear to have changed all that much. Here, she's pictured as a happy mama sporting a warm drink and a tiny baby bump.

Sources: www.usmagazine.com, www.people.com, www.vogue.com