Your pregnancy and baby guide
12-week pregnancy dating scan
Open all pages about Your pregnancy and baby guide
- Secrets to success
- Am I pregnant?
- Early days
- Week by week
- Preparing for the birth
- Work out your due date
- Tests scans and checks
- Your pregnancy (antenatal) care
- Your health and wellbeing
- Existing health problems
- Common pregnancy ailments
- Pregnancy-induced conditions
Labour and birth
- The start of labour
- The birth
- Emotions and worries
- Premature babies
- How to breastfeed
- Breastfeeding problems
- Lifestyle and breastfeeding
- Bottle feeding
- Newborn screening tests
- Newborn essentials
- New parents
- New mums
- Twins and multiples
Babies and toddlers
- Weaning and solid foods
- Baby health and care
- Spotting signs of serious illness
- Reflux in babies
- How to take a baby's temperature
- Reducing the risk of SIDS
- Treating a high temperature
- Sleep problems in children
- Coughs, colds and ear infections
- Diarrhoea and vomiting
- Infectious illnesses
- Children's medicines
- Looking after a sick child
- Serious conditions and special needs
- Constipation in young children
- Your baby's height and weight
- Baby health and development reviews
- Leg and foot problems in children
- Learning, play and behaviour
- Safety and accidents
All pregnant women in England are offered an ultrasound scan at around 8 to 14 weeks of pregnancy. This is called the dating scan. It's used to see how far along in your pregnancy you are and check your baby's development.
Your midwife or doctor will book you a dating scan appointment. It will usually take place at your local hospital ultrasound department. The person performing the scan is called a sonographer.
You may need to have a full bladder for this scan, as this makes the ultrasound image clearer. You can ask your midwife or doctor before the scan if this is the case. The dating scan usually takes about 20 minutes.
Find out more about what happens during a pregnancy ultrasound scan.
What is the purpose of the dating scan?
The purpose of the dating scan is to check:
- how many weeks pregnant you are and work out your due date (the estimated date of delivery, or EDD)
- whether you're expecting more than 1 baby
- that the baby is growing in the right place
- your baby's development
This scan can detect some health conditions, such as spina bifida.
Does screening for Down's syndrome happen at the dating scan?
This depends on whether you have agreed to have the screening and when the scan takes place. Screening for Down's syndrome will happen at the dating scan if:
- you have agreed to have screening for the condition
- the scan takes place between 10 and 14 weeks of pregnancy
The screening test for Down's syndrome used at this stage of pregnancy is called the "combined test". It involves a blood test and measuring the fluid at the back of the baby's neck (nuchal translucency) with an ultrasound scan. This is sometimes called a nuchal translucency scan.
The nuchal translucency measurement can be taken during the dating scan. If you have agreed to have screening for Down's syndrome, the dating scan and the screening will usually happen at the same time.
Find out more about the combined screening test for Down's syndrome.
You will not be offered the combined screening test if your dating scan happens after 14 weeks. Instead, you will be offered another blood test between 14 and 20 weeks of pregnancy to screen for your chance of having a baby with Down's syndrome. This test is not quite as accurate as the combined test.
Find out more about:
You can also read Screening tests for you and your baby, from Public Health England.
Page last reviewed: 04/10/2019
Next review due: 04/10/2022