Having an Ultrasound When You Are Pregnant: Brief Version

Why is ultrasound used?

Ultrasound uses sound waves to make a picture of your baby inside your uterus. An ultrasound scan can help your healthcare provider check the health of the baby. Your provider can also use it to look at your uterus, amniotic sac, placenta, and ovaries. You may be able to find out if your baby is a boy or a girl, but that is not usually the reason for having an ultrasound. It is a very safe test that will not hurt you or the baby.

Ultrasound can help your healthcare provider:

• Find out how far along you are in the pregnancy.
• Check the baby's growth.
• Figure out how much the baby weighs.
• Measure the baby's bones, head, and abdomen.
• Check the baby's heart.
• Look for movement by the baby.

It can also help your healthcare provider check for problems. For example, he or she can:

• Make sure the baby is growing inside the uterus.
• Check for more than 1 baby.
• See if the placenta is normal and attached to the uterus the right way.
• See how the baby is lying in the uterus.
• Check for problems with the uterus.

What happens during the ultrasound?

Your healthcare provider may want you to have a full bladder when the ultrasound is done. He or she may tell you:

• Drink about 6 glasses of water an hour before the ultrasound.
• Do not urinate the hour before your ultrasound.

An ultrasound takes about 15 minutes. It does not hurt you or your baby.

The person who does the ultrasound may be your healthcare provider or a technologist. He or she will:

• First put a gel on the skin of your abdomen.
• Then move a wand, called a transducer, slowly over your abdomen.

The wand sends and picks up sound waves. It then makes a picture on the screen. You can see the picture as the wand moves over your belly. It can be hard to tell what you are seeing. Your healthcare provider can help explain what parts of the baby you are seeing.

Sometimes ultrasound is done through the vagina, especially early in a pregnancy. Then it is done with a wand shaped like a narrow tube.

Talk to your healthcare provider if you have questions about having an ultrasound, or what it shows.