All service users are offered ultrasound examinations (scans) during their pregnancy to provide an estimated due date, to detect multiple pregnancy and to check the baby’s development.
Ultrasound scans use sound waves to build a picture of the baby in the womb. The scans are painless, have no known side effects on mothers/parents or babies, and can be carried out at any stage of pregnancy. Talk to your midwife, GP or obstetrician about any concerns you have.
Having a scan in pregnancy is usually a happy event but be aware that ultrasound scans may detect some serious health conditions, so try to be prepared for that information.
What will happen at the scan?
Most scans are carried out by sonographers. The scan is carried out in a dimly lit room, so the sonographer is able to get good images of your baby.
You'll be asked to lie on your back and reveal your abdomen.
The sonographer will put ultrasound gel on your abdomen, which makes sure there is good contact between the machine and your skin.
The sonographer passes a probe over your abdomen and an image of the baby will appear on the ultrasound screen.
During the exam, sonographers need to keep the screen in a position that gives them a good view of the baby.
The sonographer will carefully examine your baby's body. The sonographer may need to apply slight pressure on your tummy to get the best views of the baby.
How long will a scan take?
A scan usually takes around 20 to 30 minutes. However, the sonographer may not be able to get good views if your baby is lying in an awkward position or moving around a lot.
If it's difficult to get a good image, the scan may take longer or must be repeated at another time.
When are scans offered?
Hospitals in England offer at least 2 ultrasound scans during pregnancy:
- at 10 to 14 weeks
- and between 18 and 21 weeks
The first scan is sometimes called the dating scan. The sonographer estimates when your baby is due (the estimated date of delivery, or EDD) based on the baby's measurements.
The dating scan can include a nuchal translucency (NT) scan, which is part of the combined screening test for Down's syndrome, if you choose to have this screening.
The second scan offered during pregnancy usually takes place between 18 and 21 weeks of pregnancy. It's sometimes called the mid-pregnancy scan. This scan checks for 11 physical conditions in your baby.
You may be offered more than 2 scans, depending on your health and the pregnancy. You can find out more about the 12-week dating scan and the 20-week or mid-pregnancy scan.
Do I have to have ultrasound scans?
No, not if you do not want to. Some people want to find out if their baby is more likely to have a condition, while others do not. The 12-week dating scan and 20-week scan will be offered to you, but you do not have to have them.
Your choice will be respected if you decide not to have the scans, and your antenatal care will continue as normal. You'll be given the chance to discuss it with your maternity team before making your decision.
Can I bring family or friends with me when I have the scan?
Yes. You may like someone to come with you to the scan appointment.
Children are not permitted to attend scans as childcare is unavailable.
An ultrasound scan is an important medical examination, and it is treated in the same way as any other hospital investigation. Ultrasound scans can sometimes detect abnormalities with the baby.
Click here to find out more information about antenatal scans:
