3D ultrasound scans are still colour pictures of your baby in three dimensions. 4D ultrasound scans on the other hand are moving 3D images of your baby, with time being the fourth dimension.

In other words, 3D scans are similar to the coloured photos you see in newspapers and magazines. A 4D scan will be mostly recorded on a DVD and given to you.

The ideal time to have a 3D or 4D scan is between 24 and 30 weeks. This is because, before 24 weeks the baby has much fat beneath the skin, so the facial bones show through the skin. After 32 weeks the baby may get into more difficult positions to scan, so technically may be more challenging and the face may not be well visualised.

If you’re not able to get good views of your baby’s face, you may still be able to see her fingers and toes.

3D and 4D scans will be more expensive but will give you a better bonding experience because you might be able to see your baby’s face. From a medical point of view, the benefits of 3D and 4D scans over 2D scans appear to be limited.

However, 3D and 4D scans can occasionally be useful in giving additional information about a known abnormality. This is because, these scans can show more detail from different angles. So, they can help in the diagnosis of problems such as cleft lip. This can help doctors plan the repair after birth. 

3D scanning can also be useful to look at the heart and other internal organs.

3D and 4D scanning is considered safe in Fetal scanning.