What is an ultrasound/scan?

A pregnancy ultrasound or scan, is an imaging test that uses sound waves to see how a baby is developing in the womb. These scans are used during the course of the pregnancy to monitor fetal growth and development.  Ultrasound waves cause no harm to the mother or fetus

Are all scans the same?

Some things are looked at in every scan, others relate to pregnancy duration & fetal size. Every scan should document the number of fetuses, the fetal heart beat, the size of the fetus and development of the fetal organs. The scan will also check the position of the placenta (afterbirth) and the amount of fluid around the fetus (amniotic fluid). This will always be done using 2D scans.

While measuring and examining the fetus, one can sometimes detect the development of structural abnormalities in the fetus. Fortunately most fetuses are normal but in about 5% an abnormality is present. Some defects are minor, others severe or fatal. Not all parents want to know before the birth whether their fetus is normal or not because they may feel too upset when a problem is detected many weeks before the birth. This can be very distressing to parents. To look for abnormalities in the fetus is therefore optional. If you don’t want to be informed about any abnormal findings in the fetus, you must tell the person examining you before the scan is started.

Do i need a full bladder?

The shape of the modern probes means that the scan can be done with an empty bladder. Try not to drink too much fluid prior to the scan.

Can i bring family to see the ultrasound?

Husbands or partners are always welcome in the ultrasound room. Family members & children are not allowed into the examination room. This is because the room is also used for sterile procedures and like any medical examination, scans take anything from 30-60 minutes.

What is 3D & 4D ultrasound?

Those beautiful pictures that you see in magazines are known as 3D ‘surface rendered’ images. In other words, the ultrasound machine uses sophisticated software to construct an image of the baby as you would see it ‘with the skin on’. The technology is similar to that used to make animated cartoons like Shrek, so that the image you see on the ultrasound monitor is really a computer-constructed image, not a true peek at the baby itself. In order to get a beautiful 3D ultrasound image, the baby’s face must not be covered by hands or touching anything. Just like any picture, if the baby isn’t looking at the ‘camera’, you can’t get a good image. When the baby’s face is clear, the image can be astounding. But, if the hands, the cord, or something else is blocking the view, we can’t get that gorgeous shot like in the promotions. Don’t count on getting a great image every time. 

What does 3D & 4D Scans look like?

First of all, 4D is simply a series of single 3D images so that there is the appearance of motion. The 4th dimension is time. The important thing to remember when you look at any 3D/4D image is that it is a computer-constructed image, not a glimpse at the real thing. As such, the computer can make some odd assumptions as it is trying to render a realistic surface to the baby and weird bulges and lumps appear.  4D scans are used in the detailed examination of the heart, fetal echocardiography.

How accurate is pregnancy dating?

A dating ultrasound of the length of the embryo when performed at 7-11 weeks gestation is accurate to within about 3 days. Beyond this time the accuracy reduces due to flexion (bending) of the fetus and individuals growth variance.

What is down syndrome?

The term ‘syndrome’ is used to describe a collection of features which are often seen together. Down syndrome was first identified by Dr John Langdon Down in 1866, who noticed a similarity in appearance in some of his patients. These individuals possessed a broad, flat face, a thick tongue and a small nose and were intellectually impaired to a variable degree.


However, there are more differences than similarities between people with Down syndrome. Many babies with the condition will have one or all of the following features at birth: low muscle tone (a floppy baby), a face that appears flatter with eyes slanting upward, small ears and a wider neck than usual, a crease across the palm of the hand and a gap between the toes. Some may have heart problems. While intellectual disability is a feature of the syndrome, those with the condition will develop and learn throughout life, but at a slower pace than usual.


There is no cure for a child born with this condition but many symptoms can be treated and special early intervention programs are enabling these individuals to develop their potential. A child with Down syndrome can usually do most things that any young child can do such as walking, talking, dressing and being toilet trained although they may do these things later than other children.

What part of the baby will be seen?

You will notice a dramatic difference in the anatomic detail visible in your baby on this scan when compared to the 12 week scan.


The ultrasound will endeavour to evaluate the fetal brain, face, spine, heart, lungs, stomach, kidneys, bladder, cord insertion at the belly button, arms and legs, placenta cervix and amniotic fluid.