20-week Anomaly scan 

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What is this information about?

This information is about your Anomaly pregnancy scan. It explains:

• why you are having this scan 
• what you need to know before your scan  
• what we look at in this type of scan 
• what happens after your scan. 

Why I have I been given this information?

You have been given this information because you have chosen to have the 20-week screening scan. This information will help make sure that you are prepared for your scan and that we get the best information possible about you and your baby. This will help us care for you during your pregnancy, delivery (when your baby is born) and postnatally (after your baby is born). 

Why am I having an anomaly scan?

Your anomaly scan is to check the development and growth of your baby. This scan is offered to everyone, but you do not have to have it if you do not want to.

What measurements of my baby will the Sonographer do at the anomaly scan?

The Sonographer will take measurements of your baby. This includes measuring:

• around your baby’s head. This is a Head Circumference (HC) measurement 
• an area of fluid in part of your baby’s brain called the posterior ventricle (VP) 
• part of your baby’s brain called the cerebellum (TCD).  
• around your baby’s tummy. This is an Abdominal Circumference (AC) measurement  
• the length of your baby’s thigh bone. This is a Femur Length (FL) measurement.

Which parts of my baby’s body will you check at the anomaly scan?

The Sonographer will check your baby’s: 

• head and brain 
• spine  
• heart  
• stomach 
• kidneys 
• bladder  
• arms and legs (including hands and feet but not how many fingers and toes your baby has) 
• face  

What are the 11 conditions the Sonographer will be checking for?

Anomaly scans give Sonographer’s the chance to check for 11 rare conditions. The scan is looking for differences in body parts that might tell us if your baby has any of these conditions. We will be checking for the following conditions: 

• anencephaly 
• open spina bifida 
• cleft lip 
• diaphragmatic hernia 
• gastroschisis 
• exomphalos 
• serios cardiac anomalies 
• bilateral renal agenesis  
• lethal skeletal dysplasia  
• Edward’s syndrome (T18) 
• Patau’s syndrome (T13) 

You can find out more information about each of these conditions, including treatment options by following the links on this page :

What else will the Sonographer be checking for at my scan?

The Sonographer will also check around your baby. They will look at the position of your placenta and the ‘water’ (amniotic fluid) around your baby. If your placenta cannot be checked over the top of your tummy you may be offered an internal (vaginal) scan, as this can give us a clearer view of your placenta.  

Sometimes your doctor may ask us to check your cervix (the opening to your womb) with an internal scan or the blood flow to your womb using a uterine artery Doppler scan.  

When in my pregnancy will I be able to have my 20-week anomaly scan?

We can offer you your anomaly scan when you are between 18 and 21 weeks pregnant.  

We will book your scan based on your estimated due date (EDD).  

If you do not think that you will be between 18 weeks and 21 weeks pregnant at the time of your scan, please contact the ultrasound booking team. They may ask you some questions to help make sure we scan you at the right time.   

Will I be able to find out the sex of my baby?

If you want to know the sex of your baby, then please let the Sonographer know before your scan. If it is possible to check, then your Sonographer will give you an opinion as to whether your baby is male or female. Please note this is not 100% accurate. Checking the sex of your baby is not part of the health checks we do, so this will only be done if you ask the Sonographer. 

What happens after my scan?

• For most people, the Sonographer will explain the results of your scan to you.  
• We will give you a printed copy of the results (scan report) and a copy will also be uploaded to your Badgernotes (your electronic pregnancy notes).  
• If you do not understand the results or if you have any questions or concerns, do ask your Sonographer at the time of your scan. 

What happens if there are unexpected findings at my scan, which show that there be concerns for the health of me or my baby?

• If there is anything on the scan which does not look as we would expect, your Sonographer will tell you. 
• If we are not sure about anything on your scan you may see someone from our ‘Screening team’ this could be a specialist midwife or doctor who will give you more information after the scan.  
• Sometimes we need to arrange more detailed scans; scan later in the pregnancy or extra tests before we can get any extra information about you or your baby. 
• These extra scans or tests may be at different hospitals. 
• For some people unexpected findings come back with no problems once a specialist has had a closer look.  

How can I find out more about preparing for my scan?

If you have not been sent a copy and cannot view this online, please phone our ultrasound booking team to ask for a copy. 

Antenatal ultrasound booking teams

Who should I contact if I still have questions about my anomaly scan?

For more detailed information, you can access the Fetal Anomaly Screening Programme (FASP) information at: