Your guide to the 12-week dating scan

Your 12-week ultrasound is a chance for you to see your growing baby for the first time. It’s a milestone that can make things start to feel very real, especially if this is your first baby. 

If you’ve known you’re pregnant for a while now, and you’re waiting until your first scan to share the exciting news of your soon-to-be new arrival, it can feel like a long wait!  In the meantime, explore our guide on what to expect at your 12-week scan and how you can prepare. 

Unless you’ve chosen to have or been offered an early pregnancy scan, your 12-week scan is likely the first ultrasound you’ll have. It’s also known as the dating scan because it provides a more accurate estimated due date. 

Despite the name, the 12-week scan can take place anywhere between weeks 10 and 14 of your pregnancy¹. It’s usually carried out by a sonographer who will check¹:

• How far along you are - this will help to predict your due date
• Whether you’re expecting more than one baby
• That your baby’s developing as expected 

The 12-week ultrasound appointment typically lasts around 20 minutes and the scan is harmless to both you and your baby¹.

During your 12-week ultrasound, you’ll also be offered a nuchal translucency scan, which is a screening test for Down’s syndrome, Edwards’ syndrome and Patau’s syndrome¹.

If you decide to have the screening, your sonographer will use the ultrasound scan to measure the fluid at the back of your baby’s neck, which is called ‘nuchal translucency’. You might also have a blood test. Together, these tests can help determine the chances of your baby being born with a genetic difference².

You don’t have to have a nuchal scan at 12 weeks – it’s a personal decision that’s entirely up to you³. Your midwife will discuss your options with you and will be able to answer any questions you may have.

The nuchal translucency scan won’t tell you whether your baby does or does not have Down’s syndrome, Edwards’ syndrome or Patau’s syndrome. But it can tell you if there’s a higher or lower chance of your baby being born with one of these conditions³.

If your screening test shows a higher chance, you’ll be offered an appointment to discuss the test results and the options available³ . You can also reach out to charities such as Antenatal Results and Choices (ARC) for more information and support.

Getting ready for your 12-week ultrasound scan? Take a look at our top tips to make sure you’re prepared:

• You might need to have a full bladder to make the ultrasound image clearer. Ask your midwife or doctor before the scan if that’s the case¹.
• Wear comfy clothes that are easy to undo or take off. A top you can pull up and loose trousers you can pull down are perfect as they mean you don’t have to get undressed. ‘The gel can be messy, not to mention cold! I’d recommend wearing something washable just in case it gets on your clothes.’ (Sylvie’s mum).
• Some hospitals offer a picture of your baby from the ultrasound scan, usually for a small charge. Make sure you bring a payment method if you’d like to take a photo home⁴.
• You can usually bring a partner, friend, or family member with you to your 12-week scan appointment. Many hospitals prefer children not to attend, so you may need to arrange childcare if you have other children⁴.

Your next pregnancy scan will most likely be your 20-week scan⁵.

Until then, here are some ways you can prepare for the rest of your pregnancy and your new arrival⁶:

• Antenatal classes give you more information on what to expect during birth and beyond and are a great place to meet other soon-to-be parents⁷. You can ask your midwife about local options. ‘Antenatal classes were a real help to my partner and me. Many of my friends already had children, so it was nice to be on this journey with other mums at the same stage as me. We’ve stayed in touch too, I made some friends for life.’ (Sebastian’s mum).       
• Keep eating a healthy, balanced diet to give you and your baby all the nutrients you need as your pregnancy progresses⁸.
• Move your body – even gentle exercise can help your body prepare for labour and keep your endorphins flowing⁹. ‘Swimming was great during pregnancy. The feeling of taking the weight off and having that time for myself felt amazing!’ (Oliver’s mum). 
• Pay attention to your emotional and mental wellbeing. If you’re feeling anxious or low, talk to loved ones or lean on your healthcare team for support¹⁰.

No, it’s too early to tell the gender of your baby at your 12-week scan. If you’d like to know your baby’s gender before they’re born, you might be able to find out at your 20-week scan¹¹.

Yes, you can choose not to have a 12-week ultrasound scan¹¹. You’ll have the chance to discuss your options with your midwife before you make a decision.

The 12-week scan itself usually takes around 20 minutes¹ . It’s a good idea to block out plenty of time in your day in case the waiting times are longer than expected.

Your 12-week ultrasound scan may pick up your baby’s heartbeat¹², although this isn’t routine in all hospitals . However, you may be able to see your baby’s heart beating on the screen. Ask your midwife or sonographer if you have any questions or concerns.

It’s usually possible to tell if you’re having twins, and even whether they’re identical or non-identical, at your 12-week scan¹³ . There’s always a very small chance that twins could be missed, but this becomes less and less likely as your pregnancy progresses.