Tommy's PregnancyHub

Ultrasound scans

An ultrasound scan is a way of looking at your baby in the womb. Scans can check the date your baby is due, tell whether you’re having more than one baby and pick up on some possible problems.

You will be offered at least two ultrasound scans during your pregnancy as part of your routine antenatal care. If there are any issues and your baby needs more checks you might have more scans. Like all the other tests and procedures, you can choose whether or not to have the scans on offer.

The first routine scan is offered at around weeks 11 to 14 of your pregnancy. The timing of scans can be a bit different depending on where you live and when you first see your doctor or midwife.

Seeing your baby for the first time can feel like an exciting event. You may feel anxious too. You can bring your partner, a friend or a family member along with you to share it.

How do ultrasound scans work?

An ultrasound scan uses sound waves to show your baby on a screen.

During the scan, you lie on an examining table. The scanner (sonographer) will spread a gel over your tummy and then roll a small scanning device around the area where the gel is. This sends pictures of what's going on in your womb to a computer screen.

The pictures on the computer can be printed out so you get your first photos of your baby!

Where will I have my ultrasound scans?

Most people have their ultrasound scan done at their local NHS hospital or through their private healthcare provider. There are also independent baby scanning services that offer ultrasound scans. 

All baby scanning services offering diagnostic procedures that use ultrasound in the UK must be registered with the Care Quality Commission (CQC). If the service is not registered they may be practising illegally and without appropriate insurance. 

Find out more about choosing a baby scanning service

What are the scans looking for in pregnancy?

At 8 to 14 weeks

The first scan:

At 18 to 21 weeks

The second scan, known as the ‘fetal anomaly scan' shows:

  • how your baby is growing
  • the health and position of your placenta
  • if there are any visible problems with the way your baby’s body is developing.

Fetal anomaly scans do not have a 100% detection rate. This means that in a small number of cases there may be problems with the baby’s development that the sonographer can’t see and a baby may be born with an abnormality.

Most scans show that the baby is developing normally because most babies are healthy. But if you have any symptoms that worry you, or you just feel that something is wrong, don’t rely on the results of a recent scan or wait until your next one. Contact your midwife or local maternity unit.

When can I tell if I am having a boy or girl?

At your second scan, the sonographer may be able to see if your baby is a boy or a girl.

Tell them if you would like to know – and tell them too if you don’t want to find out until the birth.

The point of the scan is to check the health and growth of your baby and some hospitals may have a policy of not looking at gender. And your baby might be lying in a position that doesn’t let the sonographer see the gender.

Just for fun, see whether old wives' tales can predict if you're having a girl or a boy on the BabyCentre website.

Can I have extra scans during my pregnancy?

Although there is no evidence that scans are unsafe for your baby (unlike X-rays, which should be avoided in pregnancy), doctors can’t yet be sure that there is no risk at all to your baby. Because of this, it’s not advisable to keep ‘looking’ unless your doctor or midwife needs to know more about your baby’s wellbeing.

You can pay privately to have 3D scans (three-dimensional still pictures of your baby) or 4D scans (moving 3D images of your baby) but you should be aware that this involves extra unnecessary ultrasound scans.

If you choose to use an independent baby scanning service, make sure they are registered with the Care Quality Commission (CQC).

What if I'm expecting twins or more?

Women expecting twins or triplets will be offered more scans than women having a single baby.

If your first scan shows you are having twins or triplets, the scanner will check to see whether they share a placenta or not. This is because babies who share a placenta can have a higher risk of problems during the pregnancy.

Very rarely, twins or triplets will also be in the same amniotic sac. If this happens, you’ll be looked after by an obstetrician who has lots of experience of this kind of pregnancy.

You will be offered extra scans later in your pregnancy to check how your babies are growing. If your babies share a placenta, you will probably be offered growth scans more often than if they each have their own placenta.

1, National Institute for Health and Care Excellence (2017) Antenatal Care. Appendix D: Antenatal appointments (schedule and content), NICE Clinical Guideline 62: 

2. NHS Fetal Anomaly Screening Programme (2015)

3. National Institute for Health and Care Excellence (2008) Antenatal Care. Statement 1.10: Fetal growth and well-being, NICE Clinical Guideline 62: 

4. National Institute for Health and Care Excellence (2011) Multiple pregnancy: The management of twin and triplet pregnancies in the antenatal period, NICE Clinical Guideline 129:  

5. CKS.  Antenatal care – uncomplicated pregnancy.!topicsummary (Page last reviewed: September 2016.)

6. NHS Choices. Ultrasounds in Pregnancy. (Page last reviewed: 30/11/2017. Next review due: 30/11/2020)

Review dates
Reviewed: 05 July 2018
Next review: 05 July 2021

This content is currently being reviewed by our team. Updated information will be coming soon.