Which prenatal assessment procedure provides images of the fetus to monitor proper development?

On this page

• What is an ultrasound scan?
• Why do I need an ultrasound scan?
• What routine scans might be offered during pregnancy?
• Why else might I need an ultrasound during pregnancy?
• Can an ultrasound scan hurt my baby?
• Do I need to have ultrasound scans?
• Who performs an ultrasound scan?
• How do I prepare for an ultrasound scan?
• How much does an ultrasound cost?
• When will I get the results of my ultrasound scan?
• More information
• Related information on Australian websites

What is an ultrasound scan?

An ultrasound is a procedure that uses soundwaves to create images of your baby while it’s in the uterus (womb). During the scan, gel is placed on your abdomen (tummy) and a probe called a transducer is placed against your skin. Pulses of sound waves are then sent from the probe to your baby, creating echoes that are turned into images by computer. You can see these images on a monitor.

In some situations, your doctor might prefer a transvaginal ultrasound to get better pictures of your baby. In this case, you will be covered with a sheet while the probe is inserted into your vagina. The probe would be moved around in the vagina to take pictures of your baby. It may be a little uncomfortable, but it shouldn’t hurt

Why do I need an ultrasound scan?

Ultrasounds are a simple, pain-free way to check how your pregnancy is progressing, and to provide helpful information on how your baby is developing. For example, they can:

• confirm your pregnancy (and check for multiple pregnancies, for example, twins)
• check your baby’s age and estimated due date
• see how your baby’s organs and other structures are developing
• check your baby’s position in your uterus
• examine your cervix and the placenta
• check the amniotic fluid around your baby

What routine scans might be offered during pregnancy?

Several types of scan are routinely recommended during pregnancy.

Dating scan: This ultrasound is usually done in the first trimester, between 6 and 10 weeks of pregnancy, to help date your pregnancy, and estimate your baby’s due date. It can also confirm how many babies you are carrying, check that your baby is growing well in your womb, and is not ectopic (outside the uterus).

Nuchal translucency scan: This ultrasound can be done between 11 weeks, 3 days and 13 weeks, 6 days of pregnancy. It measures the amount of fluid behind your baby’s neck. This measurement, known as the ‘nuchal translucency’, is used — together with your age, weight and blood test results — to calculate the risk that your baby may have a chromosomal abnormality, such as Down syndrome.

Morphology scan: A morphology scan (also known as a ‘fetal anomaly scan’) is an ultrasound done between 18 and 20 weeks of your pregnancy. It checks your baby’s body organs, specifically looking at their structure and growth, while their age can be estimated based on these measurements. This scan can also check your baby’s heart rate and rhythm, show whether you have more than one baby in your uterus, and where your placenta is lying. Depending on your baby’s position, the scan may also reveal the sex.

Why else might I need an ultrasound during pregnancy?

In some cases, your doctor might recommend a third trimester ultrasound scan to assess your baby’s wellbeing and growth. The third trimester ultrasound also gives your healthcare team information about the location of your placenta and helps assess your cervix.

Can an ultrasound scan hurt my baby?

Ultrasound is a safe and pain-free test, and there is no increased risk of miscarriage or harm to your baby. The sound waves used are at very low volume and so they will not hurt you or your baby and your baby will not be able to hear them.

Do I need to have ultrasound scans?

Your doctor is likely to recommend you have one or more ultrasound scans during your pregnancy so they can check how your baby is developing, but you’re still free to choose whether or not you have the scan.

Talk to your doctor or midwife about tests and scans to understand why they might be offered to you.

Questions you might want to ask your doctor

Here are some questions you might want to ask your midwife or doctor:

• Why are you offering me this test?
• What does the procedure involve, do I need to do anything on the day?
• When will I get the results?
• Who will contact me to give me the results?
• Do I need to do anything to care for myself after the procedure?

More questions to ask your doctor about tests and scans.

Who performs an ultrasound scan?

Some medical specialists, such as obstetrician, have had specialised training and are certified to carry out ultrasound scans. In other cases, your doctor may refer you to an imaging clinic where a trained ultrasound operator known as a sonographer will check your baby. You might have your ultrasound in a community clinic, an imaging centre or in a hospital.

Ask your health team if you can have printed copies of your baby’s ultrasound images to take home.

How do I prepare for an ultrasound scan?

The ultrasound clinic will tell you how to best prepare for your scan. Some clinics will ask you to drink 3 glasses of water 1 hour before the appointment and to not go to the toilet or empty your bladder until you’ve had your scan. This is because a full bladder makes it easier to see the images. Other clinics recommend eating and drinking normally, but ask that you do not empty your bladder within 30 minutes of your appointment.

Please check with your clinic what they prefer when you book your appointment what they would prefer you to do.

How much does an ultrasound cost?

Medicare will cover part of the cost of your ultrasound scans. Ask your doctor if you should expect any out-of-pocket costs for your specific situation.

When will I get the results of my ultrasound scan?

The results from the scan will be available on the same day as you have it. A copy of the report will be sent to your referring doctor. If there are any abnormalities found in the scan, a specialist doctor will contact you to discuss what they mean.

More information

One of the aims of having ultrasound scans in pregnancy is to offer a safe, accessible test that can provide you with more information about your unborn baby. While these scans can reassure you that your baby is developing normally, you may also learn that your baby has an abnormality. For this reason, before you have the test it’s a good idea to think about why you are choosing to do it, and how you will feel once you get the results. Consider also who you might want to discuss any important decisions with. Your partner, a friend or family member, or a health professional such as your GP or midwife are all good options.

If the results of your ultrasound bring up any concerns about genetic conditions, you can talk to your doctor or midwife about other diagnostic tests, such as chorionic villus sampling or amniocentesis, for these conditions.

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