Sometimes known as a Fetal Anatomy Scan or 20 Week Scan this scan is where the sonographer is able to examine the anatomy of your baby in great detail.
When can I have an Anomaly Scan
The Anomaly Scan can be performed from 18 to 22 week. The reason the Anomaly Scan isn't performed earlier in the pregnancy is because all your baby's internal organs aren't fully formed.
After 24 weeks a full anatomical examination may not be possible because your baby will often adopt a less helpful position to obtain clear views.
Why is the Anomaly Scan important
The Anomaly Scan is important because it is the best opportunity during your pregnany to examine all the anatomy of your baby in great detail.
It is critical that any abnormalities are detected at this stage so that a management plan can be formulated for the remainder of the pregnancy, for the delivery and if necessary after your delivery if post natal treatement is required.
It also allows the parents sufficient time to prepare or make difficult decisions on rare occasions where a severe abnormality is discovered
If you are having your scans on the NHS this is usually the last scan that you will have in your pregnancy.
How accurate is the Anomaly Scan
The accuracy of the Anomaly Scan mainly depends on how clearly the sonographer is able to see all the important parts of your baby's anatomy.
The Anomaly Scan is a big checklist for the sonographer to complet.It is for this reason that sometimes you may have to be scanned several times and walk around in between to encourage your baby to move into a better position.
Therefore the accuracy of the Anomaly Scan is dependent on the sonographer ability to complete every item on the list.
Your baby's growth and a well being assessment are also part of the examination.
What will I see at the Anomaly Scan
During the Anomaly Scan your sonographer will spend the majority of the appointment looking at various anatomical details that may not be immediately recognisable to the untrained eye.
This can be a confusing or unnerving experience for the parents. The Anomaly Scan is performed in conventional 2D ultrasound so that internal organs may be examined. It is not possible to scan in 3D or 4D nor would it offer any greater accuracy or detail. If you ask most sonographers will have a quick peek at babies sex, but please remember the most important thing is making sure all is well with baby and some times the sexing of your baby is not possible.This is usually the time at which most parents really start to bond with their baby.
How does the Anomaly Scan Scan work
During the appointment your sonographer will:
- Show your baby’s heart beating and check the rate
- Check growth by measuring the head, waist and thigh bone (femur) of your baby
- Look at your placenta and the amount of fluid around your baby
- Examine the structure of your baby’s organs in detail (a checklist of over 30 items)
All the measurements and information will be added into your pregnancy record for comparison with earlier and subsequent later scans