One of the first things that crosses your mind when you realize you are pregnant is probably going to be “when should I get an ultrasound scan”. These regular scans throughout your pregnancy are vitally important. They track your health, the wellbeing and development of your baby and can pick up any anomalies. It’s also important to have the ultrasounds as often as your doctor suggests to ensure that development is happening at the correct rate.

How does an ultrasound work?

The wand – the piece of the ultrasound that is put to your stomach – emits sound waves. These then bounce off of solid surfaces within your abdomen. The wand then receives these returned waves and the machine creates an image from the data.

This test is completely harmless to both mother and baby. You can also go for as many scans as you like without any worries about causing damage.

Why get ultrasound scans when pregnant?

These scans will tell the doctor a lot about your pregnancy and help them to track your progress. In the early stages, an ultrasound will show you how far along you are, how many babies you have and whether you have a normal or ectopic pregnancy.

After this first scan, your doctor will recommend how often and how many follow up scans you should have throughout gestation. These are necessary to monitor fetal development, body growth and the health of the placenta.

When do you have ultrasound scans?

Your first ultrasound will most likely be scheduled for week eight of your pregnancy. If you have the scan any earlier than this, you may not be able to see anything aside from the gestational sac or even be able to hear the heartbeat. This is because the embryo is too small and may be missed on the scan. If the ultrasound is done too early, you may end up feeling very frustrated and even worried. Listen to your doctor’s recommendations and try not to panic.

In this first ultrasound, you should be able to see signs of your pregnancy even if you can’t see the actual embryo. The gestational sac and a thicker endometrium are definite signs that you have conceived. The embryo will appear from week eight onwards. The heartbeat can usually be heard from this time too.

Most gynecologists will require that you have at least three ultrasounds throughout your pregnancy – one in each trimester. The first one at around week eight. The next two will happen in the following two trimesters. In most cases, this is sufficient to monitor fetal development and growth, as well as detect any problems or medical issues.

In some cases, especially if your healthcare plan will cover it, your doctor may want to do an ultrasound every month. This can be good to put your mind at ease and give you a chance to see the incredible changes happening inside of you.

What you can expect at each stage

  • At 7-8 weeks: This will show you the exact gestational age so you can accurately predict your due date. It will also show the number of embryos developing in your womb.
  • At 12 weeks: The nuchal translucency test is done at this stage. It detects possible chromosomal conditions, such as Down syndrome.
  • At 20 weeks: This is the morphology ultrasound that is always done around the midway point of gestation. Your doctor will check every detail about the growth and development of your baby, including skeletal structure, function of the organs and the state and position of the placenta.
  • At 27 weeks: The maturity of the placenta needs to be checked at this stage, usually with a Doppler ultrasound. This shows the blood flow to and from the fetus, as well as circulation around the body.
  • At 33 weeks: This final ultrasound can be done to check on the amount of amniotic fluid surrounding your baby. Your doctor will also look at the position of the fetus to see if it is ready for birth.

If at any point your doctor sees something that doesn’t seem right, you may have extra ultrasounds scheduled. These will then be done more often to ensure that things stay on track and to help your doctor to monitor potential problems in more detail.

Ultrasounds have some extra benefits – not just checking on your wellbeing and that of your baby. You get to discover the sex of your baby before he or she comes out into the world. You can see this as early as week 12, but it’s best to wait until week 16 to be sure.

3D and 4D ultrasounds

Standard ultrasounds are done in 2D, but if you want a closer look, you can also get them done in 3D and 4D. The 3D scan gives you a wonderful, in-depth look at the features of your baby while it’s still inside the womb. The 4D scan will then give you a video of all of these details. You’ll be able to see the contours of your baby’s face and then see things like little yawns or your baby sticking out its tongue.

These scans are usually done at around 32 weeks. If you do them any earlier, your baby won’t be fully developed and you won’t get a good idea of what the features will look like after birth. If you wait any longer, you may not be able to see the details because of the lack of space in the womb.

The 3D and 4D scans can be quite expensive and aren’t covered by most healthcare plans. However, they are well worth doing because you get to enjoy a beautiful moment and get to meet your baby a little bit earlier.

Readers’ questions:

Does an ultrasound hurt or harm you?

Ultrasound scans are perfectly safe for both you and your baby. They do not hurt at all and can’t harm you. This is why it’s absolutely fine to get several scans done throughout your pregnancy.

Is it possible for errors to occur on an ultrasound?

Yes, it is possible for your doctor to interpret what they see incorrectly. The scan will show what is there and your doctor will have to make an interpretation of that image. The most common errors occur when trying to tell the gender of the baby.