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Prenatal care

  • Prenatal care is the care you get while you’re pregnant.
  • Regular prenatal care helps keep you and baby healthy.
  • A doctor, midwife or other health provider gives this care.
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Ultrasound

Ultrasound (also called sonogram) is a prenatal test offered to most pregnant women. It uses sound waves to show a picture of your baby in the uterus (womb). It lets your provider check on your baby’s health and development.

Ultrasound can be a special part of pregnancy—it’s the first time you get to “see” your baby! Depending on when it’s done and your baby’s position, you may be able to see his hands, legs and other body parts. You may be able to tell if your baby’s a boy or a girl, so be sure to tell your provider if you don’t want to know!

Most women get an ultrasound at 18 to 20 weeks of pregnancy. You may get a first-trimester ultrasound (called an early ultrasound) to confirm your pregnancy (make sure you’re pregnant) and find out your due date.

What are some reasons for having an ultrasound?
Your health care provider uses ultrasound to check your baby’s growth and development and to help estimate your baby’s due date. Ultrasound checks for several things, including:

Are there different kinds of ultrasound?
Yes. The kind you get depends on what your provider is checking for and how far along you are in pregnancy. All ultrasounds use a tool called a transducer that uses sound waves to create pictures of your baby on a computer.

The most common kinds of ultrasound are:

  • Transabdomial ultrasound. When you hear about ultrasound during pregnancy, it’s most likely this kind. Your provider moves the transducer across your belly. To get a better picture, he covers your belly with a thin layer of gel. This helps the sound waves move more easily. The ultrasound takes about 20 minutes. You may need to have a full bladder during the test. This prevents pockets of air in your bladder from affecting the picture. Ultrasound is painless, but having a full bladder may be uncomfortable.
  • Transvaginal ultrasound. This kind is done in the vagina (birth canal). It also takes about 20 minutes. For this test, your bladder needs to be empty or just partly full. The ultrasound is painless, but you may feel some pressure from the transducer.

In special cases, your provider may get more information using other kinds of ultrasound, like:

  • Doppler ultrasound. This is used to check a baby’s blood flow if he’s not growing normally.
  • 3-D ultrasound. This takes thousands of pictures at once. It makes a 3-D image that’s almost as clear as a photograph.
  • 4-D ultrasound. This is like a 3-D ultrasound, but it also shows your baby’s movements.

Does ultrasound have any risks?
Ultrasound is safe for you and your baby when done by your health care provider. Because ultrasound uses sound waves instead of radiation, it’s safer than X-rays. Providers have used ultrasound for more than 30 years, and they have not found any dangerous risks.

If your pregnancy is healthy, ultrasound is good at ruling out problems, but not as good at finding them. It may miss some birth defects. Sometimes, a routine ultrasound may suggest that there is a birth defect when there really isn’t one. While follow-up tests often show that the baby is healthy, false alarms can cause worry for parents.

You may know of some places, like stores in a mall, that aren’t run by doctors or other medical professionals that offer “keepsake” 3-D or 4-D ultrasound pictures or videos for parents. The American College of Obstetricians and Gynecologists, the Food and Drug Administration and the American Institute of Ultrasound in Medicine do not recommend these non-medical ultrasounds. The people doing them may not have medical training and may give you wrong or even harmful information.

What happens after an ultrasound?
For most women, ultrasound shows that the baby is growing normally. If your ultrasound is normal, just be sure to keep going to your prenatal checkups.

Sometimes, ultrasound may show that you and your baby need special care. For example, if the ultrasound shows your baby has a heart problem, she may be able to be treated in the womb before birth. If the ultrasound shows certain birth defects or that your baby is breech (feet-down instead of head-down), you may need a cesarean section (c-section).

No matter what an ultrasound shows, talk to your provider about the best care for you and your baby.

More information
The March of Dimes has partnered with the American Institute of Ultrasound Medicine, Johns Hopkins University and Parents.com to create a unique peak into a baby's development inside the womb. These images reveal the details of a baby's growth from a collection of cells to a full-term newborn.

Last reviewed June 2012

See also: Your first prenatal care checkup, Later prenatal checkups

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Frequently Asked Questions

What is transabdominal ultrasound?

When you hear about ultrasound during pregnancy, it’s most likely a transabdominal ultrasound. This is a prenatal test that uses sound waves to show a picture of your baby in the uterus (womb). Your health care provider uses it to check your baby’s health. Most women get an ultrasound at 18 to 20 weeks of pregnancy.

During an ultrasound, your provider moves a plastic tool, called a transducer, across your belly. The transducer sends sound waves into your uterus. The waves bounce around to create a picture of your baby on a monitor. To get a better picture, your provider covers your belly with a thin layer of gel. This helps the sound waves move more easily.

Your provider measures your baby’s body throughout the test. Depending on your baby’s position, your provider may point out his hands, legs and other body parts. You should be able to tell if your baby’s a boy or a girl, so be sure to tell your provider if you don’t want to know!

You may need to have a full bladder during the test. This prevents pockets of air in your bladder from affecting the picture. Ultrasound is painless, but having a full bladder may be uncomfortable.

What is first trimester ultrasound?

First-trimester ultrasound (also called early ultrasound) is a prenatal test that uses sound waves to show a picture of your baby in the uterus (womb). Some providers may use this kind of ultrasound to make sure your baby’s organs are growing and developing normally.

Your health care provider uses it to check your baby’s health. A first-trimester ultrasound takes place before 14 weeks of pregnancy.

The kind of first-trimester ultrasound you have depends on the type of information your provider needs. Your provider usually does ultrasound by moving a plastic tool, called a transducer, across your belly. This is called transabdominal ultrasound. You also can have a transvaginal ultrasound, which means it’s done in the vagina (birth canal). Both kinds usually take about 15 to 20 minutes.

Your provider can use first-trimester ultrasound to:

See also: Ultrasound

What is 4-D ultrasound?

4-D ultrasound is a prenatal test that uses sound waves to show a three-dimensional picture of your baby in the uterus (womb) and shows your baby’s movement. 3-D images are almost as clear as a photograph, and 4-D is a moving-picture version or video. Some providers may use this kind of ultrasound to make sure your baby’s organs are growing and developing normally.

You may know of some places, like stores in a mall, that aren’t run by doctors or other medical professionals that offer “keepsake” 3-D or 4-D ultrasound pictures or videos for parents. The American College of Obstetricians and Gynecologists, the Food and Drug Administration and the American Institute of Ultrasound in Medicine do not recommend these non-medical ultrasounds. The people doing them may not have medical training and may give you wrong or even harmful information.

What is 3-D ultrasound?

3-D ultrasound is a prenatal test that uses sound waves to show a three-dimensional picture of your baby in the uterus (womb). Some providers may use this kind of ultrasound to make sure your baby’s organs are growing and developing normally.

The 3-D ultrasound is almost as clear as a photograph. A moving-picture version is called 4-D ultrasound.

You may know of some places, like stores in a mall, that aren’t run by doctors or other medical professionals that offer “keepsake” 3-D or 4-D ultrasound pictures or videos for parents. The American College of Obstetricians and Gynecologists, the Food and Drug Administration and the American Institute of Ultrasound in Medicine do not recommend these non-medical ultrasounds. The people doing them may not have medical training and may give you wrong or even harmful information.

See also: Ultrasound

What is Doppler ultrasound

Doppler ultrasound is a kind of prenatal test that can be used to check a baby’s health in high-risk pregnancies. Providers usually use Doppler ultrasound during the last trimester, but it may be done earlier.

During Doppler ultrasound, your provider uses a plastic tool called a transducer to measure the blood flow in the umbilical cord and some of your baby’s blood vessels. This test shows if your baby is getting enough oxygen. Your provider also can listen to your baby’s heartbeat using Doppler ultrasound.

Some providers use Doppler ultrasound to check mothers with Rh disease. This is a condition where a difference between the mother’s blood and baby’s blood can cause a dangerous kind of anemia in the baby. Anemia is when the body doesn’t have enough red blood cells or the red blood cells are too small. When the condition is found early and treated, most affected babies survive.

What is transvaginal ultrasound?

Transvaginal ultrasound is a prenatal test that uses sound waves to show a picture of your baby in the uterus (womb). Your health care provider uses transvaginal ultrasound to check your baby’s health. It’s often used for early ultrasound in the first trimester.

During the test, your provider moves a thin, wand-like transducer into the vagina. You lay on your back with your feet in stirrups during the exam. You may feel some pressure from the transducer, but it shouldn’t cause pain.

Transvaginal ultrasound can be used throughout pregnancy to check for problems with the cervix (opening to the uterus) and lower uterus.

See also: Ultrasound

How is blood pressure measured?

Blood pressure is the force of blood that pushes against the walls of your arteries. Arteries are blood vessels that carry blood away from your heart to other parts of the body. If the pressure in your arteries becomes too high, you have high blood pressure. High blood pressure is also called hypertension.

At each prenantal care visit, your health care provider checks your blood pressure. To do this, she wraps an inflatable cuff around your upper arm. She pumps air into the cuff to measure the pressure in your arteries when the heart contracts (gets tight) and then relaxes.

Your blood pressure reading is given as two numbers: the top (first) number is the pressure when your heart contracts and the bottom (second) number is the pressure when your heart relaxes. A healthy blood pressure is 110/80. High blood pressure happens when the top number is 140 or greater, or when the bottom number is 90 or greater

Your blood pressure can go up or down during the day. Your provider can re-check a high reading to find out if you have high blood pressure during pregnancy.

Last reviewed March 2012

See also: High blood pressure during pregnancy, Preeclampsia, HELLP syndrome

Can a rubella shot hurt my baby during pregnancy?

If you got your rubella shot around the time you got pregnant, it's unlikely that your baby will be harmed by the vaccine. However, it's best to wait to get pregnant for 28 days after vaccination because there is a very small risk of potentially hurting the baby. To date, there hasn't been any birth defects reported that are attributed to the rubella vaccine. In any case, the risk of harming your baby by getting the vaccine at the time you got pregnant is much lower than the risk of harming your baby if you caught rubella during pregnancy.

I couldn't see my baby at my 7 week ultrasound. Why?

At the 7th week of pregnancy, your baby is about ½ an inch long or the size of a blueberry. He's very small. When a transabdominal ultrasound (done on your belly) is done at such an early stage, it's possible that the baby can't be seen. It could be because it's too early in the pregnancy or because you conceived a little later than what you thought. Your health care provider might recommend a transvaginal ultrasound (done inside the vagina) to help see the baby more clearly.

What are choroid plexus cysts?

The choroid plexus is the area of the brain that produces the fluid that surrounds the brain and spinal cord. This is not an area of the brain that involves learning or thinking. Occasionally, one or more cysts can form in the choroid plexus. These cysts are made of blood vessels and tissue. They do not cause intellectual disabilities or learning problems. Using ultrasound, a health care provider can see these cysts in about 1 in 120 pregnancies at 15 to 20 weeks gestation. Most disappear during pregnancy or within several months after birth and are no risk to the baby. They aren't a problem by themselves. But if screening tests show other signs of risk, they may indicate a possible genetic defect. In this case, testing with higher-level ultrasound and/or amniocentesis may be recommended to confirm or rule out serious problems.

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