Our specially trained team performs a wide variety of ultrasound examinations. They check that your pregnancy is going as planned with anomaly and growth scans. This involves making a diagnosis from images seen on an ultrasound monitor.
Your doctor or midwife will explain at what stage in your pregnancy you may have an ultrasound scan. You will usually be referred to the hospital for this type of examination.
Before your ultrasound examination
Please remember to bring your maternity notes (orange or purple book) with you. If you have any questions before your appointment, please call the number on the right of this page.
All scanning takes place on the 8th floor of North Wing at St Thomas' Hospital, in either the fetal medicine unit or the ultrasound department.
Changing or cancelling your appointment
If you need to change or cancel your appointment for any reason, please call:
- 12-week scan and fetal medicine appointments, tel 020 7188 8003
- 20-week scan, ultrasound department, tel 020 7188 5547.
Please tell us as soon as possible so we can give your appointment to another patient.
At your ultrasound examination
The examination takes around 20-30 minutes. The sonographer (specialist who performs the ultrasound exam):
- applies ultrasound jelly to your abdomen (tummy). This helps to get a clear picture on the screen
- checks your baby to check their development
- takes several measurements of your baby and plots these on a chart
- enters the report into your maternity notes.
Sometimes it is not possible to get a clear picture due to the way the baby is positioned at the time of your examination. If this is the case, the sonographer will discuss this with you and may ask you to return on another date for a repeat examination.
Please ask the sonographer at your appointment if you have any questions or if you would like an ultrasound picture of your baby.
Examples of ultrasound images
The report will be placed in your maternity notes and the midwife or doctor who referred you for the scan will discuss the results with you.
We are continually improving our service to offer an excellent standard of care. To make a suggestion, please fill out one of our comment forms available from the reception desk.
How to find us
St Thomas' Hospital
8th floor, North Wing
Westminster Bridge Road
London SE1 7EH
Tel: 020 7188 5547 (ultrasound department)
Tel: 020 7188 8003 (fetal medicine unit)
Map to the antenatal clinic (PDF 1Mb)
Concerned about you or your baby?
If you are worried about yourself or your baby (for example, you feel unwell, or you have not felt your baby move as much as usual), don't delay, contact the maternity helpline:
Or call the maternity assessment unit.
- Tel: 020 7188 1722, 8am-8pm every day.
At other times, please ring the Hospital Birth Centre on 020 7188 6867.
Research we support
iFIND: intelligent Fetal Imaging and Diagnosis - finding new technologies that allow scanning to be carried out with multiple ultrasound probes and improved fetal ultrasound imaging through automated image processing.
Developing Human Connectome Project (dHCP) - aiming to make major scientific progress by creating the first 4-dimensional connectome of early life.