From early pregnancy to the anomaly scan, ultrasounds check that your baby is developing as it should be. We look at what scans you can expect on the NHS and what’s available privately.
What is an ultrasound scan?
When you go for a pregnancy scan, the sonographer (a specialist trained in ultrasound scans) puts ultrasound gel on your tummy and then moves a handheld probe across your skin. While the gel might be a bit cold, the scans are completely painless.
The probe sends out ultrasound waves – sound waves with a frequency higher than the human ear is able to hear – to produce images of your baby, which the sonographer studies on a screen.
Ultrasound scans in pregnancy have several purposes:
- They check your baby’s size and, at the early pregnancy dating scan, help calculate your due date.
- They monitor whether your baby is growing normally.
- They check whether you’re having one baby, twins or more.
- They can detect some abnormalities.
- They can show if you have too much or too little amniotic fluid.
- They show the position of the placenta and your baby, which can affect whether you can plan to give birth vaginally or if you might need a caesarean.
Are pregnancy scans safe?
Ultrasound scans have been used for many years, and there are no known risks to you or your baby from having the routine scans offered in pregnancy.
If you’re considering a private 3D or 4D scan, it’s worth considering that these scans often last longer, meaning your baby will be exposed to more ultrasound than they are during routine NHS scans.
While there’s no evidence to suggest that this is unsafe, it’s recommended that non-medical scans are avoided in the first 10 weeks of pregnancy, as the embryo is potentially more vulnerable at this early stage, according to a paper published in 2015 by the Royal College of Obstetricians and Gynaecologists.
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What pregnancy scans are offered on the NHS?
All pregnant women in England, Scotland, Wales and Northern Ireland should be offered at least two ultrasound scans on the NHS as part of their antenatal appointments schedule.
You might be offered more than two scans – for example, if there are concerns about your health or your baby’s growth. But for most women having straightforward, healthy pregnancies, the early pregnancy scan and the anomaly scan are all that are recommended.
The early pregnancy scan
Taking place between 8 and 14 weeks, the early pregnancy scan, or dating scan, is your first pregnancy scan.
The dating scan will establish how far along you are and give you an estimated due date. It will check whether you’re expecting one baby or more and that your baby is developing as it should be at this stage.
You should also be offered an antenatal screening test for Down’s syndrome and other chromosomal abnormalities at this stage. This is called the combined test, because it involves a blood test as well as the scan, and can be carried out between 10 and 14 weeks. It’s also sometimes referred to as the NT (nuchal translucency) scan.
The test can’t tell for sure whether your baby has Down’s syndrome or another similar condition but can identify whether they’re at risk. It takes up to two weeks to get the results, but you should be told within three working days if your baby is at high risk. Based on the result, you might choose to have further tests to get a definitive answer.
If you’d rather not know about possible risks, you can have the dating scan without the combined test. Talk to your midwife about how to arrange this.
The anomaly scan
Between 18 and 21 weeks, you’ll have your anomaly scan, which is sometimes called the mid-pregnancy scan.
The sonographer will take a detailed look at your baby’s heart, brain, bones, spinal cord, face, kidneys and abdomen to check for a range of conditions. Not all problems can be detected by the anomaly scan, but if the sonographer sees any cause for concern, you’ll be told there and then.
What scans are available privately?
As well as the routine NHS scans, there are several different types of private scan that you might consider.
Between 6 and 10 weeks you can have a scan to see whether your pregnancy is developing normally. You’ll see a beating heart, and if you have the scan towards then 10 week mark you can also see the head and the where your baby’s little limbs are forming.
This scan can be reassuring if you’ve had a previous miscarriage or are feeling very worried. However, it’s important to note that if you experience any problems like pain or bleeding early in your pregnancy you should always contact your GP, midwife or the Early Pregnancy Assessment Unit (EPAU) first – they might be able to give you a scan without you having to pay to have it done privately and also do other checks to make sure you and your baby are healthy.
Sonographers can usually tell you the sex of your baby at your NHS anomaly scan at around 20 weeks. However, sometimes it’s not possible to tell the sex at that scan as your baby might be in a position that makes it difficult for the sonographer to see, in which case you may want to have a private scan to check the sex later on.
If you’re really keen to know the sex of your baby as early as possible, you can have a private gender scan from as early as 16 weeks.
3D and 4D ultrasound scans
In the second half of your pregnancy, you can get a really clear view of your growing baby through a private 3D or 4D scan.
- 3D scans provides static three-dimensional images of your baby.
- 4D scans shows your baby moving around in real time.
You might see your baby doing things such as sucking their thumb, stretching, yawning and kicking. You should also be able to find out the sex, and usually get a selection of pictures and, in the case of 4D scans, video to take home.
Before 26 weeks your baby hasn’t put on a lot of fat and so will look very skinny and the bones of the face will show through, and after around 32 weeks your baby is more squeezed up and running out of space, so it’s harder to get clear pictures.
How much do private scans cost?
The price you’ll pay for non-NHS scans depends on the type of scan you want, how many private scans you have and the area you live in.
A survey we ran in 2019 showed that while 18% of people who had private scans paid less than £50, 10% of parents spent more than £500.
|Amount paid for private scans||Percentage of parents who paid this amount for scans|
|Less than £50||18%|
|More than £200||20%|
Why do people have private scans?
According to our survey of parents in 2016, around one in seven pregnant women pay for a private scan, mainly because they want a 3D or 4D scan.
Of these, 36% arrange extra scans for reassurance that all’s well. The advice from the National Institute for Health and Clinical Excellence (NICE) is to have your early scan and then the anomaly scan at 18-20 weeks. Feeling anxious about your baby is quite natural during the early stages of your pregnancy and if you have any concerns you should consult your midwife first.
Just over a third book a private scan to find out the sex and 16% want extra pictures of their baby.
One in ten women decides to go private to see a specialist, and 4% book a scan because they or their partner have an underlying medical condition.
What if a scan uncovers a problem?
If a scan reveals a possible problem with your pregnancy or baby, the sonographer might ask for a second opinion from another professional. This might be done straight away or you may have to come back for another scan.
You might be offered further tests to give you more information about the problem, but you won’t have to make an instant decision about whether to have them. You’ll be able to discuss it with a midwife or doctor who can explain what’s involved and, in some cases, you might be referred to a specialist.
It’s always upsetting if antenatal screening tests or scans uncover a problem, but support is available from doctors, midwives or specialist support groups.
The established charity ARC, which stands for Antenatal Results and Choices, can provide information and support. It has extensive online advice and a helpline that you can call to help you understand the information the midwives and doctors have given you and make the right decisions for you and your family.
More from Which?
- Why choosing where to give birth matters: Find out how having your baby at home, in a birth centre or in a labour ward can affect your birth experience.
- Budgeting for a baby: A guide to getting your family finances in order before your baby arrives.
- Who will look after you during pregnancy and labour? We run through the different midwives and doctors you might meet.
These are the sources of information used in this article:
NICE, Antenatal care for uncomplicated pregnancies, NICE Clinical Guideline 62, London: National Institute for Health and Clinical Excellence
NHS, Ultrasound scans in pregnancy, NHS Choices website
Royal College of Obstetricians & Gynaecologists, Ultrasound from Conception to 10+0 Weeks of Gestation, (Scientific Impact Paper No. 49), London