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Fetal anomaly scan

Fetal Anomaly Scan

This scan is usually performed between 18+0 to 20+6 weeks of pregnancy and is offered as part of the NHS ‘fetal anomaly’ ultrasound screening programme. This section of the website gives you some information about the purpose of the ultrasound scan, so you can decide whether or not to have this examination.

Why am I offered a mid-pregnancy scan?

The main purpose of this scan is to look for abnormalities in your unborn baby.

Is the scan safe?

As far as we know, the scan we offer is safe for mothers and babies.

What kind of scan will I be offered?

You will be offered a scan that produces a two-dimensional (2-D) black and white image that gives only a side view of the baby.

Does everybody have a scan?

We offer the scan to everybody, but you do not have to have it if you do not want to. Before making up your mind, there are a few things you do need to know, so please read this section carefully.

Giving permission for the scan

Remember that this is a medical examination. You will be asked to give your permission for it to be carried out. Make sure you understand what is going to happen. Feel free to ask any questions.

What can a scan tell me about my baby’s health and development?

Before deciding whether or not to have a scan, you need to know what scans can and cannot tell you. During the scan, we take a very close look at your baby. We usually learn that the baby appears to be healthy and is developing well, but sometimes we find a problem. If this happens it will be explained to you.  Some problems are quite common, others are very rare and they will be explained to you.

Scans are not guaranteed to find all problems. Sometimes we have to say there might be a problem, but we cannot say for certain. In a small number of cases, babies are born with abnormalities that were not spotted by the scan.

 Sometimes, the sonographer may not be able to get good views if your baby is lying in an awkward position or is moving around a lot, this can reduce the quality of the image. If it is difficult to get a good image, the scan may take longer, or have to be repeated at  and this will be explained to you.

If everything appears normal, what happens next?

Most scans show that the baby is developing normally, and no problems are found. This is because most babies are healthy and do not have abnormalities.

Will the sonographer tell me the sex of my baby?

Finding out the sex of your baby is not offered as part of the national screening programme, but if you specifically request to know the sex of your baby the Sonographer will endeavour to give you this information.  However this is sometimes not possible due to the baby's position and in approximately 6% of cases nationally, the incorrect sex will be given.

Will the scan say for certain whether or not there is a problem?

Not always. As we explained earlier, not every abnormality can be spotted by a mid-pregnancy scan. This means that in some cases, babies are born with abnormalities when no problem was identified by the scan.

What problems can you see?

Major structural abnormalities in the development of the baby such as spina bifida, are usually obvious on the scan and the sonographers and doctors can be absolutely certain of the findings. Scans are not so reliable at seeing problems such as some heart defects and we do not expect to pick up every heart condition before birth.

Sometimes minor changes in the baby’s body are seen. Usually these mean nothing at all, but sometimes we see a pattern which tells us there could be an underlying problem.  Some minor problems may need follow-up care after the baby is born.

What will happen if a problem is found, or suspected, during the scan?

If any problem is found or suspected, the sonographer may ask for a second opinion from another sonographer or clinician. You would then be told what the concerns were, but the exact problem might not be clear at this stage.

If necessary, you will be referred to a specialist. You should be given an appointment within a few days.

In most cases, further tests do not find a problem. However, any extra test can cause great anxiety for parents, and for some people the anxiety can last throughout the rest of the pregnancy.

You might be offered another test, such as an ‘amniocentesis’, to find out for certain if there is a problem. If you are offered further tests you will be given more information about these tests. You can then choose whether or not you want to have them. 

You may want to ask questions and to talk about your worries with your own midwife or consultant. There is also a specialist screening midwife available if required.

What will happen if a type of abnormality is definitely found?

This depends on the type of abnormality and how serious it is. Some abnormalities may turn out not to be serious and some get better on their own. In either of these cases you may be offered further scans throughout your pregnancy to monitor the condition.

If the condition is serious someone will talk you through your options, which may include ending the pregnancy. If you need to make any decision, your midwife and the hospital team will give you time, support and information and they will respect your choice.

Can anything be done before the birth?

Finding out about a condition before birth can help parents prepare themselves, and sometimes it can help to plan treatment after the baby is born. For example, if your baby is known to have a problem that will need an operation soon after birth, such as the repair of a hernia in your baby’s tummy, arrangements can be made to deliver your baby in a hospital where this can be done within the first few hours after birth.

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