Pregnant Belly Shape And Size: A Month-By-Month Guide

upclose of woman holding her pregnant belly

While you’ll notice a change in your breasts, the urge to start nesting, and maybe even pregnancy brain, to everyone else, the clearest sign that you’re expecting a little one is your pregnant belly!

Since you’re tuned in to all things baby right now, you’ve no doubt noticed the size and shape of your pregnant friends’ bellies and wondered about your own.

Just like our bodies, pregnant tummies come in all shapes and sizes, but you probably still have questions.

Should you be concerned about the size of your belly? What affects the size and shape? When will you start showing? And what sort of growth should you expect each trimester?

Newton Baby is here to answer those questions! First, let’s talk about whether or not the size of your pregnant belly is something to add to your list of things to worry about.

Does The Size Or Shape Of Your Pregnant Belly Matter?

Woman in street holding her pregnant belly 

What you see on the outside — the general size and shape of your belly — doesn’t have much to do with your baby, their health, or their size. A healthy baby can grow regardless of how your belly looks.

During your second trimester, your doctor will start taking fundal height measurements. This is a better way to tell whether your baby is big or small for their gestational age and can be an indicator of conditions like slow fetal growth or too much or too little amniotic fluid.

If you feel worried about the size or shape of your bump, by all means, talk with your doctor about it! They will check it out and put your mind at ease.

But for now, rest assured that no matter how your pregnant belly looks on the outside, as they say, “it’s what’s inside that counts.”

What Affects The Appearance Of Your Pregnant Belly?

upclose side view of pregnant belly

Why do pregnant bellies look so different if babies develop the same on the inside? Several factors can affect how you carry your baby, when you start to show, and how big (or small) your belly looks.

Let’s talk about a few of them.

Your Muscle Tone

Yes, your pre-pregnancy six-pack (or lack thereof) does affect how your bump will look!

Having tight abs before you get pregnant might mean that you don’t show as quickly and that you carry your baby higher once the baby bump appears.

While abdominal muscle tone may affect the size and shape of your pregnant belly, remember you don’t need super-defined, fitness-model muscles to be healthy.

A gentle, safe exercise program during pregnancy is important, as is postpartum exercise.

Your Height

Whether you’re tall or short can affect your bump.

Tall pregnant women with long torsos tend to carry in front since the baby has room to push up, while short pregnant women tend to have a belly that pushes outward and is a bit more spread out.

Due to body shape and height, pregnant bellies can also create an optical illusion. Your bump might seem bigger or smaller than your friend’s bump when really they’re the same size.

How Many Pregnancies You’ve Had

First born kissing mom's pregnant belly

If this isn’t your first rodeo, you might show a baby bump sooner than you did with your first pregnancy and carry a bit differently.

This is because, for second and third (and fourth and fifth!) pregnancies, your ligaments, muscles, and uterus are already a bit stretched out.

How Many Babies You’re Carrying

If you’re expecting more than one baby, your pregnant belly will grow differently to accommodate twins or triplets.

Don’t be surprised if you show earlier than expected or your tummy grows to be quite big!

Your Pregnant Belly Month By Month

Since pregnant moms have bellies of all shapes and sizes and grow at different rates, there’s no way to say exactly what’s “normal.”

But, in this section, we’ll give you an idea of what you’ll see and feel, the size of your uterus, and the size of your baby each trimester.

Months 1 Through 3 (First Trimester)

woman touching first trimester pregnant belly

Your first trimester lasts through week 12, so it’s the first three months of your pregnancy. Keep in mind that pregnancy lasts about 40 weeks, so you’re pregnant for closer to 10 months than nine.

What You’ll See

You may notice that your pants fit a bit differently, but some women don’t see any sort of baby bump during the first trimester!

As we mentioned, when you start showing depends on your body, whether you’ve had previous pregnancies, and how many babies you’re carrying.

Even if you feel a tiny bump, it’ll probably be a while before other people notice. If you think you are showing a bit at this stage, it could also be due to extra water or bloating.

The Size Of Your Baby

It makes sense that you don’t show much (or at all) during the first trimester because your baby is very tiny! Your baby goes from a fertilized egg at conception to being around three inches long by week 12.

The Size Of Your Uterus

Your uterus begins growing during the first trimester but can still stay snug inside your pelvis.

The American Pregnancy Association says that your pre-pregnancy uterus is the size of an orange, and by week 12 of gestation, “the uterus is the size of a grapefruit and starts to grow up and out of your pelvis, but still fits within it.”

Months 4 Through 7 (Second Trimester)

Woman in nursery holding pregnant belly

Your second trimester lasts a little over three months, from weeks 13 through 27, and is when your doctor will start taking fundal height measurements.

They’ll use a tape measure to check the length from your pubic bone to the top of the uterus. This gives your doctor an idea of whether your baby is small or large for their gestational age.

The fundal height is measured in centimeters, and after 24 weeks, this measurement is usually about the same as the week of pregnancy.

For example, if you’re 26 weeks pregnant, your fundal height measurement will be around 26 centimeters. If your measurement is off, it may only mean that your due date was calculated incorrectly.

Ask your doctor if you have questions or concerns.

What You’ll See

Sometime during the second trimester is when you’ll really start to notice your baby bump!

It will probably be visible to others at the beginning of the second trimester, and by the end of this trimester, your pregnant belly will likely be in full swing.

The Size Of Your Baby

Your baby does a lot of developing and growing during this trimester! They’ll go from around four inches long to 12 or 15 inches by the end.

The Size Of Your Uterus

With all the growing your baby is doing, how much does your uterus grow to accommodate them?

According to the American Pregnancy Association, “your uterus will grow to the size of a papaya. It no longer fits inside the pelvis. It will be situated midway between the navel and breasts.”

Months 8 Through 10 (Third Trimester)

Pregnant woman with partner hugging her

Your third trimester is the home stretch! It begins at week 28 and lasts until 40 weeks, more or less, depending on when your baby decides to come.

What You’ll See

If you haven’t worn maternity clothes up to this point, the third trimester is when you’ll need them! Your pregnant belly will grow bigger by the day.

Some women look like they’re carrying a small basketball up to the day they go into labor, while others look like they’re about to pop during the whole trimester!

The Size Of Your Baby

During your third and last trimester, your baby grows to around 18 or 20 inches — how long they will be when you hold them for the first time!

The Size Of Your Uterus

This is as big as your uterus will get!

The American Pregnancy Association says, “The uterus will finish growing and be the size of a watermelon. When you reach full term your uterus will extend from the pubic area to the bottom of your rib cage.”

There’s no doubt your uterus takes up a lot of room now! Because it pushes on your bladder, lungs, and stomach, you may have heartburn, shortness of breath, and find yourself making frequent trips to the bathroom at night.

Love Your Pregnant Belly

mom holding newborn

No matter the size or shape, whether you’re big or small, or carrying low or high, your pregnant belly is the perfect place for your baby to develop and grow!

Love your bump and get excited for your little one on the way.

Use our guide to get an idea of what your tummy might look like during each trimester and how big your baby and your uterus are. And when you near the end of your pregnancy, prepare your baby’s nursery with a Newton Baby Crib Mattress.

In no time at all, your baby will be out of your tummy and in your arms!