Fetal anomaly scan
This scan is offered at 18 to 20 weeks of pregnancy.
How long will my scan take?
The fetal anomaly scan usually takes about 20 to 30 minutes.
The scan is done to:
- check your baby’s physical development
- help detect structural changes (also called anomalies) such as spina bifida, kidney conditions, or heart conditions
- check the amount of fluid around your baby in the womb, and
- look at the position of the placenta
Looking for the sex of your baby is not part of the scan and is not 100% accurate.
If you want to know the sex of the baby and the sonographer can see it, they will tell you at the time of the scan. They will not write it down.
Will I need another fetal anomaly scan?
The sonographer will use an all-Wales agreed checklist to look for certain conditions (such as spina bifida) and at structures (such as the heart). The sonographer has to concentrate very hard during the scan, so may seem quiet during the scan but they will update you when they can.
Sometimes it is not possible to see everything on the list during your scan.
This can be because:
- your baby was lying in a position which made the examination difficult
- you are above average weight for your height and this made looking at your baby difficult as the images were not clear.
If this happens, you will be given another appointment to come back for one more scan to see if the sonographer can complete the checklist. It is not always possible for the sonographer to complete the list, even on the second appointment.
What will happen if an unexpected finding is suspected during the scan?
If the sonographer detects an unexpected finding, they will tell you about it and you will be able to talk to the midwives and hospital doctor (obstetrician) in your antenatal clinic. Receiving unexpected news can be upsetting. We recommend that your partner or one adult only comes with you to the scan appointment.
Sometimes it is not possible, at the first fetal anomaly scan, for the sonographer to tell definitely what the unexpected finding is. You might be offered another scan in a different department or with a specialist dealing with the type of condition your baby is suspected of having.