Antenatal Ultrasound

Antenatal Ultrasound is the definitive website to find an antenatal ultrasound clinic in the United Kingdom that meets your needs and delivers on your expectations. Having an antenatal ultasound is a great experience and seeing your baby for the first time can be a very emotional time. Our goal is to deliver you the best clinics and we hope you find exactly what you need.

These are our featured antenatal clinics.

Antenatal Ultrasound - Important Information

Ultrasound scans have been used in pregnancy since the Late 1960’s. Ultrasound scans are routinely used during pregnancy to monitor foetal development and to look for any anomalies with the pregnancy.

An ultrasound scan involves transmitting high frequency sound waves through the uterus. These bounce off the baby and the returning echoes are translated by a computer into an image on a screen that reveals the baby’s position and movements. Hard tissues such as bone reflect the biggest echoes and are white in the image, and soft tissues appear grey and speckled. Fluids do not reflect any echoes so appear black. It is the contrast between the different shades of white, grey and black that enables the sonographer to interpret the images.

The ultrasound scans are carried out by radiographers or midwives who are specially trained in ultrasound, they are also known as sonographers.

Ultrasound scans are carried out a various stages of pregnancy. Depending on which stage of pregnancy the scan is carried out at, ultrasounds can do the following things:

• Check your baby has a heartbeat.
• Say you are pregnant with one or more baby
• Detect an ectopic pregnancy, where the embryo implants outside the womb, usually in the fallopian tube
• Find out the cause of any unexpected bleeding
• Accurately date the pregnancy by measuring the baby
• Assess the risk of Down’s syndrome by measuring fluid at he back of the baby’s neck. This is called the Nuchal Translucency Scan.
• Find out why a blood screening test was abnormal.
• Assisting in performing diagnostic tests
• Examine your baby to see if all the organs have developed normally
• Diagnose certain abnormalities
• Assess the amount of amniotic fluid you have and locate the placenta

An ultrasound scan can tell you the sex of your baby from about 18 weeks onwards, but only if your baby will co-operate. If your baby is lying in an awkward position that it may not be possible to tell the sex of your baby. Some hospitals do have a policy of not telling women the sex of their baby as it is not always possible to be 100% accurate.

How is an Ultrasound Scan Performed?

If the scan is being performed during early pregnancy, you will need to drink several glasses of water beforehand. This is to ensure that the bladder is full enough to push the uterus out of the pelvis. This allows the sonographer to get a good picture of the baby.

The sonographer will put some gel onto your tummy and will move a small transducer over your skin to get views of the baby.

If your baby is too deep in your pelvis or if you are too overweight, the images might not be very clear, so a vaginal scan might be necessary. Vaginal scans are done in the same way as an abdominal scan except the transducer is shaped to fit comfortably within the vagina. Vaginal scans give a much clearer picture of your baby especially at a very early stage of pregnancy.

Does an ultrasound scan hurt?

An abdominal ultrasound scan is a painless procedure except for some discomfort may be caused by the transducer pressing down on your tummy if you have a very full bladder. A full bladder is not required for later scans but some hospitals still request it.

More antenatal questions answered:

Will the scan show my baby’s sex?

By 20 weeks your baby’s sex is often clear, but not all hospitals will tell you. If you want to know, check with your midwife about hospital policy.

Nuchal Translucency Scan

What is Nuchal Translucency?

This is a collection of fluid under the skin at the back of a baby’s neck at 10-14 weeks that can be measured using ultrasound. All babies have some fluid, but in many babies with Down’s syndrome, the nuchal translucency (NT) is increased.

An NT scan is a method of assessing whether your baby is likely to have Down’s syndrome. It is a screening test. A screening test can only estimate the risk of your baby having Down’s, as opposed to a diagnostic test, such as CVS or amniocentesis, which will give you a definite diagnosis (but also carries a small risk of miscarriage).

The NT scan cant tell for certain whether your baby is affected. However, it can help you decide whether or not to have a diagnostic test.

When can I have the test?

NT scans are usually performed from 11 to 13 weeks and 6 days of pregnancy. Before 11 weeks the scan is technically difficult because the baby is so tiny and, after 14 weeks excess fluid may be absorbed by the baby’s developing lymphatic system.

How is it done?

The main part of the test involves an ultrasound scan. The scan is usually done through the tummy, but depending on the position of your baby and your womb, sometimes it is necessary to perform a vaginal scan, which will give better views. There is no risk to you or your baby and it should not be too uncomfortable.

To accurately date your pregnancy, the sonographer will measure your body from the top of its head to the bottom of the spine. She will then measure the width of the NT. The skin will appear as a white line, and the fluid under the skin will look black. Your baby fits nicely on the screen, at this stage, and you will be able to see the head and spine, limbs, hands and feet. Some major abnormalities may be excluded at this scan, but it is recommended you also have a detailed scan at 20 weeks.

What is a normal measurement?

An NT measurement of up to 2.0mm is normal at about 11 weeks, and up to about 2.8mm by 13 weeks and 6 days. This is because the NT normally grows in proportion to the growth of the baby. A baby with a normal NT of 1.3mm will be classed as low risk. If the NT is increased, it does not mean that there will definitely by a problem. Some normal babies will have increased fluid. A baby with an NT of 2.9mm, which is the upper limit of the normal range, will have a higher risk factor than the baby with the NT of 1.3mm. 90% of baby’s with a measurement between 2.5mm and 3.5mm will be completely normal. As the NT increases, so does the risk. A baby with an NT of 6mm and will be very high risk for Down’s, as well as other chromosomal and genetic syndromes and heart problems. Fortunately, not many babies have as much fluid as this.

How is the risk calculated?

Every woman has a risk of giving birth to a baby with Downs syndrome, and this risk increases with age. First the database will show you the risk that applies to all women of your age, known as the background risk. The using the measurements from the scan, a new risk will be this will be generated which is your own individual risk for this pregnancy. This may be higher or lower than your background risk

When will I get the results?

Your results should be available immediately

What do the results mean?

The results will express the probability of your baby having Downs Syndrome.

Low risk is a result where the risk is less than one in 300. On your results print out this will be a ratio, fpr example 1:300. This means that out of 300 women who have this risk, one will have a baby with Down’s syndrome.

High risk is a result where the risk is greater that one in 300, for example 1:150. This means that out of every 150 women who have this risk, one will have a baby with Down’s syndrome.

Make sure that you thoroughly understand the information that the specialist gives you. Ask them to go through things again that you don’t understand.

What should I do if I am high risk?

About one in 20 women will be given a high risk and the vast majority will go on to have a normal healthy baby. Even with a risk of 1:5, the baby has four out of five chances that he does not have Down’s syndrome. Nevertheless, once your pregnancy has been labelled high risk, you will probably feel anxious and perhaps unsure of what to do.

The only way to know for certain if your baby has Down’s or other chromosomal abnormality is to have a diagnostic test such as CVS or amniocentesis. This decision can be very difficult but you do not have to decide in a hurry. One advantage of the NT scan is that it is done early in your pregnancy, and it is possible to have a CVS and get the results while you are still in your first trimester. If you are unsure what to do, you can wait until 16 weeks and have an amniocentesis then if you wish.

How reliable is a nuchal translucency scan?

A large research study involving over 100 000 pregnancies found that about 75% of babies with Down’s syndrome were correctly identified using this method. When combined with a blood test, the detection rate improves to about 90%. However, in order to achieve these detection rates, it is important that the NT is measured accurately. For this reason, strict standards have been devised so that every sonographer measures in exactly the same way. To use the database to calculate the risk, sonographers must first undergo training by the Fetal Medicine Foundation and, once they are considered competent, their technique and results are reviewed annually.

Where can I have a nuchal translucency scan?

The UK National Screening Committee recommends that the combines test (NT scan and blood test) should be offered to all women on the NHS as it has a very good detection rate. However, it is currently only available in a small number of NHS hospitals. The combines NT scan and blood test is available privately in some centres across the country, and is known as the OSCAR (One Stop Centre for Assessment of Risk).

What are 3D and 4D Ultrasound Scans?

3D scans are still pictures of the baby in three dimensions, like the photos you sometimes see in newspapers and magazines. 4D scans (with time as the fourth dimension) are moving 3D images of the baby.

You probably looked forward to your first scan, but you may have been disappointed with the grey blurry outline of a normal two dimensional image. This is because the scan sees right through the baby, so the photos show the baby’s internal organs.

With 3D and 4D scans, you see the baby’s skin covering the internal organs. You’re able to see the shape of your baby’s mouth and nose, see him yawn or stick his tongue out, and get an idea of whether he looks like Mum or Dad.

From a medical point of view the benefits of 3D and 4D scans appear to be limited. Occasionally they can be useful in giving additional information about a known abnormality. Because these scans can show more detail from different angles, they can help in the diagnosis of problems like cleft lip. This can help doctors plan the repair after birth. 3D scanning can be useful to look at the heart and other internal organs.

If you want one of these scans you will probably have to arrange for it to be done privately. The special transducers and software required to do 3D and 4D scans are expensive. As there are few clear medical benefits its unlikely that these scans will replace normal 2D scans in the near future.

These scans are just as safe as a normal scan, because the image is made up of sections on two dimensional images converted into a picture. No harmful effects have been demonstrated, but experts recommend that scans should only be carried out for medical reasons by fully trained practitioners.

The best time to have a 3D or 4D scan is between 26 and 30 weeks. Before 26 weeks your baby has very little fat under her skin, so the bones of the face show through the skin. After 30 weeks her head may go down deep into the pelvis, so you might not be able to see her face.

It’s natural that you will want to see your baby’s face on the scan, but this may not always be possible – it depends on the position of your baby. If she’s lying facing outwards, with a good pool of amniotic fluid around her features, you should be able to see her face very clearly. But if she’s facing into your back, or there’s not much fluid around her, or if you have a large amount of tummy fat, you wont see so much.

The sonographer will sometimes ask you to go for a walk, or ask you to come back in a week when your baby may have moved to a better postion.