Latest 3D and 4D scanning for observing in close detail

20 Week Anatomy and Anomaly Pregnancy Scan

The 20-week pregnancy scan is the most important prenatal screening test and is carried out by our highly trained foetal ultrasound specialist, Ms Ciara McKenna. She will check your baby’s anatomy, carefully examine for any abnormalities and test for the presence of rare conditions including those of the brain, spine or heart. 


You will be able to see detailed images of your baby in 3D and 4D (video), and our sonographer will carry out a comprehensive examination of your baby’s development so far.   


What does the 20 week anatomy and anomaly scan show?

Our scans are all carried out using the latest in advanced diagnostic technology. During your scan our sonographer will be able to: 

  • Carry out a careful check of your baby's anatomy 
  • Measure your baby's growth, including the head and brain, body and limbs 
  • Check your baby's organs and limbs for abnormalities 
  • Check and measure the placenta, amniotic fluid and the umbilical cord 
  • Identify your baby's gender
  • Show detailed images of your baby in 3D and 4D (video images) 


Can I find out the sex of my baby at the 20 week scan?

If you want to know the sex of your baby, you should be able to during this scan - as long as the genitals are not obscured. Just let our sonographer know at the start of your appointment. 


When can I book my 20 week scan?

You can actually book a 20-week pregnancy scan any time between 18 and 24 weeks into your pregnancy. You can calculate these dates from the first day of your last period.

We offer flexible appointment times to suit your schedule, including weekend and same-day appointments. This means if you have urgent concerns at this stage, you can get reassurance from our specialist sonographer at short notice. 


What conditions can we detect during the 20 week scan?

At the 20 week scan our sonographer can detect structural defects including spinal defects, cleft lip/palate, significant clubfeet, body wall abnormalities, major urinary abnormalities, and major heart defects. Our sonographer is a highly trained specialist and can identify a variety of subtle markers that may indicate Down syndrome.

Source: Radiopaedia (

Very occasionally the 20-week scan can pick up abnormalities related to chromosome disorders that might have been missed in an earlier scan. However, this is becoming less common as the accuracy of tests increases, and Non-Invasive Prenatal Testing becomes more commonplace.


What happens during the 20 week scan? 

You'll meet our specialist prenatal sonographer, Ciara McKenna, and we allow one hour for the whole appointment, so you don’t feel rushed. You’ll have time to talk through the process and ask as many questions as you need. 

She will carry out an abdominal scan, which allows her to obtain the clearest and most accurate images of your baby, and the actual scan takes around 30 minutes. 

During this time you'll be able to see the 3D images of your baby on screen, and Ms McKenna will talk you through what she’s seeing. 


What can the sonographer see?

She will look at your baby's anatomy, including organs and the placenta, and will take detailed measurements in order to calculate your baby's growth. She will check these measurements against a set of fetal growth charts, which are used to predict your baby's development. We'll keep a record of these measurements so we can compare them with your earlier and subsequent scans.

After your appointment, we will send you and your doctor a digital link where you can view the images from your scan, as well as a detailed clinical report.


What happens if the scan shows any abnormalities?

The majority of pregnancies are healthy, and this scan typically provides reassurance. In the unlikely event that any variations from normal development are detected, our sonographer is highly skilled and experienced in diagnosing prenatal complications and will be able to offer specialist advice. 

We understand how difficult this may be - she will spend as much time as you need discussing the findings and she can liaise with other specialist clinicians. We also have  expert consultants available to discuss any unexpected findings, and to help plan the next stage of your pregnancy and your post-natal care. 


Make an appointment for your 20 week anatomy and anomaly pregnancy scan

If you would like to visit our clinic for a 20 week pregnancy scan, please call 020 7244 4200 or make an appointment online