Maternity ultrasound

If you book your maternity care with Imperial, all of your ultrasound appointments will either be at Queen Charlotte's & Chelsea or St Mary's hospital.  

All women are offered a dating scan at around 12 weeks, with the option of nuchal screening. 

You will also be offered a 20-week scan between 18 weeks and 20 weeks and six days of your pregnancy. Additional scans are performed at the request of your midwife or doctor for reasons that are specific to your individual pregnancy. 

How do the ultrasound scans work?

Ultrasound scans use high-frequency sound waves to produce pictures of your baby inside the womb. This is done by building up pictures from the return of sound waves as they bounce back from resistance they meet within your body. 

Ultrasound waves are sent to and from the body using a handheld sensor (transducer), which is moved over the surface of your abdomen. The scans are painless and do not involve x-rays.  

The sonographer will explain the findings of your scan to you and there is a secondary monitor so that you and your partner can view your scan. You can also buy an image of your baby to take home. 

In addition to our regular maternity ultrasound scans, we offer 3D/4D scans of your baby, which show moving images of your baby. Please note that there is a charge associated with this additional service. 

Contact the team

You can find out more details about the maternity ultrasounds clinics and how to contact them on the, 'contact our maternity team' page.

Visiting guidelines

For more information on who can attend your maternity ultrasound scan, please visit the patient and visitors page.

Your maternity ultrasound appointment

Before your appointment

You will be referred to the ultrasound department by either your midwife or obstetrician. The routine appointments are usually scheduled at nationally recommended gestations during your pregnancy, for example at around 12 weeks for a dating scan and between 18 and 20 weeks and six days for an anomaly scan.

Your partner is welcome to attend with you. We suggest you wear loose fitting clothes, preferably that part in the middle so your abdomen can be easily exposed. Please remove any belly piercings as they can damage the utrasound tranducers. Plan your journey so you can arrive 15 minutes early for your appointment.

Please bring your maternity handheld notes along to your scanning appointments. If you would like a photograph of your baby, please bring enough change to purchase a ticket which costs £4.

During your appointment

When you arrive, please report to the reception desk within the ultrasound department. Waiting times can be up to an hour, and your scan should take 15 to 30 minutes.

Please note that we are a teaching hospital, so medical and midwifery students may be present for some appointments. If you do not wish to have them in the room please let the sonographer know and the students will be asked to step outside.

You will be invited into the ultrasound room and be asked to lie on a couch. Some gel will be applied to your abdomen and the sonographer will then move the transducer. The sonographer will explain the findings of your scan to you and there is a secondary monitor so that you and your partner can view your scan. You will have the chance to purchase a photograph of your baby if you wish.

Occasionally, the baby is in an awkward position and the scan cannot be performed right away – if this happens, we’ll ask you to go for a walk and we’ll try again later in the day. The sonographer will talk you through this, if it is necessary.

After your appointment

For the majority of women the scan is reassuring, however occasionally a problem may be found. If a problem is detected the sonographer will arrange for you to see the appropriate specialist as soon as possible, either in the early pregnancy unit or fetal medicine unit, which we work with closely.

Patient information

Having a maternity scan