What are 3D and 4D ultrasound scans?
3D scans are still pictures of your baby in three dimensions. 4D scans are moving 3D images of your baby, with time being the fourth dimension.
You're probably really excited by the prospect of your first scan. But some mums and dads find the standard 2D scans disappointing when all they see is a grey, blurry outline. This is because the scan sees right through your baby, so the photos show your baby's internal organs.
Both 3D and 4D scans are just as safe as a 2D scan, because the image is made up of sections of two-dimensional images converted into a picture. There's no evidence to suggest that scans aren't safe, and most mums-to-be gain reassurance from them.
This image is of a baby at 14 weeks. With 3D and 4D scans, you see your baby's skin covering her internal organs. You may see the shape of your baby's mouth and nose, or see her yawn or stick her tongue out.
If you'd like a 3D or 4D scan you'll probably need to arrange it privately, and you'll have to pay for it. The clinic may also give you a recording of it on DVD, though this may cost extra.
The special transducers and software required to do 3D and 4D scans are expensive. There are few clear medical benefits, and experts say they should only be done if there's a medical need. So it's unlikely that these scans will replace normal 2D scans in the future.
This image shows a baby at 26 weeks.
After 30 weeks, your baby's head may go deep down in your pelvis, so you may not be able to see her face.
The best time to have a 3D or 4D scan is when you are between 26 weeks and 30 weeks pregnant. Before 26 weeks your baby has very little fat under her skin, so the bones of her face will show through her skin. If the placenta is at the front of your uterus (anterior), it is best to wait until 28 weeks to get the best images of your baby.
It's natural that you'd like to see your baby's face on the scan. But sometimes it's not possible, depending on how she is lying.
If she's lying facing outwards, with a good pool of amniotic fluid around her features, you should be able to see her face clearly. But if she's facing your back, or if there's not much fluid around her, you won't see much. The same applies if you have a lot of tummy fat.
The sonographer may ask you to go for a walk, or to come back in a week, when your baby may have moved to a better position. If it's not possible to get good views of her face, you may be able to see her fingers and toes instead.
You're probably really excited by the prospect of your first scan. But some mums and dads find the standard 2D scans disappointing when all they see is a grey, blurry outline. This is because the scan sees right through your baby, so the photos show your baby's internal organs.
Advertisement | page continues below
This image is of a baby at 14 weeks. With 3D and 4D scans, you see your baby's skin covering her internal organs. You may see the shape of your baby's mouth and nose, or see her yawn or stick her tongue out.
If you'd like a 3D or 4D scan you'll probably need to arrange it privately, and you'll have to pay for it. The clinic may also give you a recording of it on DVD, though this may cost extra.
The special transducers and software required to do 3D and 4D scans are expensive. There are few clear medical benefits, and experts say they should only be done if there's a medical need. So it's unlikely that these scans will replace normal 2D scans in the future.
3D and 4D scans may nonetheless show more detail about a known abnormality. Because these scans can show more detail from different angles, they can help in the diagnosis of cleft lip. This can help doctors to plan the repair after birth. 3D scanning can also be useful to look at the heart and other internal organs.
This image shows a baby at 26 weeks.
After 30 weeks, your baby's head may go deep down in your pelvis, so you may not be able to see her face.
Advertisement | page continues below
It's natural that you'd like to see your baby's face on the scan. But sometimes it's not possible, depending on how she is lying.
If she's lying facing outwards, with a good pool of amniotic fluid around her features, you should be able to see her face clearly. But if she's facing your back, or if there's not much fluid around her, you won't see much. The same applies if you have a lot of tummy fat.
The sonographer may ask you to go for a walk, or to come back in a week, when your baby may have moved to a better position. If it's not possible to get good views of her face, you may be able to see her fingers and toes instead.
Images by BabyCenter
Was this article helpful?
Yes
No
Track your pregnancy on our free #1 pregnancy & baby app
Sources
BabyCenter's editorial team is committed to providing the most helpful and trustworthy pregnancy and parenting information in the world. When creating and updating content, we rely on credible sources: respected health organisations, professional groups of doctors and other experts, and published studies in peer-reviewed journals. We believe you should always know the source of the information you're seeing. Learn more about our editorial and medical review policies.
This article was written using the following sources:Tonni G, Centini G, Rosignoli L. 2005. Prenatal screening for fetal face and clefting in a prospective study on low-risk population: can 3-dimensional and 4-dimensional ultrasound enhance visualisation and detection rate? Oral Surg Oral Med Oral Path Oral Radiol Endod 100(4): 420-6
McGahan MC, Ramos GA, Landry C et al. 2008. Multislice display of the fetal face using 3-dimensional ultrasonography. J Ultrasound Med 27(11): 1573-81.
Ter Haar G. 2007. BMUS Safety Committee recommendations. Ultrasound 15(1): 47
