Fetal anomaly scan (20 – 24 weeks)

Why have a fetal anomaly scan?

After checking your baby’s heartbeat, the main purpose of this scan is to check your baby’s anatomy to see if it is all normal. A thorough examination of your baby’s brain, heart, spine, kidneys, abdominal organs and limbs will be undertaken. We also check your placenta for its position and the amount of fluid surrounding the baby. Measurements will be taken of the baby’s head, abdomen and femur (thigh bone) to ensure it is growing normally.

We are happy to tell you the gender of your baby at any scan over 16 weeks, if you wish to know. However, ultrasound is not 100% accurate and is not an absolute guarantee. It is also very easy for us not to tell you or show you the sex of your baby. If you are absolutely sure you don’t want to know then please let us know at the beginning of the scan and we will make sure we avoid the relevant area.

For high risk pregnancies we are able to scan between 22 and 24 weeks of pregnancy to measure the blood flow in the uterine arteries. These two arteries supply oxygen and nutrients to the placenta from the mother. This part of the examination is just like a normal ultrasound scan but it uses Doppler which is painless and not harmful to your baby when used by an experienced Ultrasonographer. You will see colour on the monitor as we pick up the blood vessels and hear the sound of the blood flowing through the arteries. We are looking at the blood flow because it could indicate you may have a small baby later in pregnancy. If we find that your blood flow measurement is abnormal then we will note this on your report to show your midwife or Consultant. They may want you to have follow up growth scans later in pregnancy which can be arranged at KMI or in your local hospital.


What happens if a problem is found?

The vast majority of babies we scan are normal and the anomaly scan is important as it can reassure the parents that everything appears to be as it should; however, in a few cases a potential problem may be indicated. When this happens a further follow up scan may be needed and it may be necessary for us to discuss the problem with your Midwife, GP or Consultant. The Ultrasonographer carrying out the scan will explain any complications of the pregnancy with you at the time of scan and give you advice and guidance where we can.

What is included with this scan?

We will give you a report, pictures and a DVD to take home with you. Where possible and if you would like us to we will show you your baby in 4D but good pictures using this type of ultrasound are totally reliant on the baby’s position at this stage (this will be free of charge).

If we cannot check all the anatomy at one visit and this is usually because the baby is lying in an awkward position and will not move for us so we will give you another appointment 'free' of charge to finish the scan.

Recording on a mobile phone

We are happy for you to do some recording on your mobile phone, but we ask that you keep this for personal use and do not share it on social media. The Ultrasonographer will look at your baby before you start recording to check that it has a heartbeat and that there are no major problems. None of the Ultrasonographers will provide a running commentary, they will stay quiet whilst you are recording, and we request that you do not video the Ultrasonographer undertaking your examination.

Limitations of ultrasound

Ultrasound does have its limitations which might mean we get limited views of your baby. These usually occur if: You have a high BMI, if your bladder is not full enough, if you have a lot of gas in your bowel, if there is reduced fluid around your baby and if its face is covered by its hands, or if it is looking away.