When Do Baby Bumps Start Showing in Pregnancy?

The first 12 weeks of pregnancy are called the first trimester. When a baby bump starts to show is different for everyone, but for most women the baby will fill the whole uterus and can start to protrude by 12 weeks.

The first 12 weeks of pregnancy are called the first trimester. In most cases, your baby isn’t very big, and you won’t have a baby bump during this time, though your clothes might feel tight. 

Generally, by 12 weeks, your baby will fill your whole uterus and can start to protrude. As your baby grows, they will fill up more and more of your uterus and begin to push it out. It is common to have a clearly visible baby bump by 18 to 20 weeks. 

When your baby bump shows can be different for everyone. Some women show earlier than others. This can happen if this is a later pregnancy or if you’re carrying multiple babies.

Second or later pregnancy

During your pregnancy, your abdomen muscles stretch and separate around your growing stomach. They can become weak and don’t always return to their normal position, which means you might start showing earlier.  This means in a second pregnancy or later, you might show earlier. 

Multiples pregnancy

With more babies, extra placentas, and extra fluid in your uterus, your uterus will fill quickly and might lead to showing pregnancy earlier. You also gain weight faster in your first trimester with twins or more babies.

Other reasons

A baby bump showing when you are 10 weeks pregnant can be related to your body weight and hormones. Your hormones surge to maintain pregnancy. Extra hormones can lead to swollen, tender breasts and stomach bloating. While it might look like an early baby bump, it could be bloating. If you have a small waist, you might also show earlier.

Your body changes a lot during pregnancy, but the most growth happens from the second trimester to the end of your pregnancy. During this time, your baby’s weight will multiply more than seven times. They also get longer, too.

From weeks 13 to 28, your baby grows from about 6 inches and 4 ounces to roughly 14 inches and 4 pounds. In your last trimester, from week 28 to 40, your baby grows to about 18 to 20 inches and 7 pounds. 

There are different reasons for not showing early on. 

First pregnancy

If this is your first pregnancy, it might take longer for your baby bump to show. Generally, you’ll start to show in the second trimester, though, so it isn’t something to worry about. 

Body weight

If you have obesity or a lot of belly fat, your baby bump might not show until the end of your pregnancy. For some women with obesity, your belly shape might shift, but you might not have a baby bump.

Uterus position

Some people have a tilted uterus, called a retroverted uterus, that’s tipped slightly backwards toward your rectum instead of your belly.  This is normal and doesn’t usually cause any problems, but it can mean you don’t show earlier on. By the 14th or 16th week of your pregnancy, it normally will tilt down as your baby grows and prepares for birth. 

Small baby size

A small baby bump can also indicate small for gestational age. During your pregnancy, your doctor or midwife will measure your abdomen. This is called measuring the fundal height, or the distance from your pubic bone to the top of your uterus. 

After 24 weeks, your fundal height should align with your pregnancy week, give or take 2 centimeters. If your fundal height is small, your doctor might say your baby is small for gestational age. This can happen if you’re a smaller person. 

A small fundal height can also be a sign that your baby is having growth problems. This can happen if you don't gain enough weight during pregnancy. This condition is called intrauterine growth restriction, and it can also be caused by other problems, including:

• Chromosome problems
• Placenta problems
• Disease during your pregnancy
• Twin or multiple baby pregnancy

Not enough amniotic fluid can also cause a smaller baby bump. Your fundal height doesn’t always mean there’s a problem, though. Your doctor or midwife might use fundal height simply as a guideline to monitor your pregnancy. 

Your body changes a lot during pregnancy. While some changes are common, everyone’s body is different. You might show quickly, while someone else might take longer. You might have stretch marks while someone else might not. If you’re concerned about your body and health, talk to your maternity doctor.