12 week pregnancy dating scan: here's what to expect

But what exactly should you expect? How long will it take? What will you need to do? What will the sonographer (who operates the ultrasound equipment) be looking for? Will you find out the baby's sex? Will you find out anything else?

Here, with the expert help of Gill Harrison, professional officer for ultrasound at the Society and College of Radiographers, is a clear, complete and jitter-calming guide to your first routine pregnancy scan...

Your 12-week pregnancy ultrasound scan: here's what to expect

What is the dating scan? | When will I be offered my first pregnancy scan? | Do I have to have the 12-week scan? | What does the 12-week scan show? | How do I prepare for the 12-week pregnancy scan? | What happens at the 12-week scan? | Will I see a picture of my baby on the screen? | Can I take a picture myself or take one home? | How long does the 12-week scan take? | Can I take my partner with me to the scan? | Can I take children to the scan? | Will I find out the sex at the 12-week scan? | Will I find out the results straightaway? | What will the results tell me? | I'm worried: how often does the 12-week scan find issues? | When will my next ultrasound scan be?

Why is the first pregnancy scan called the dating scan?

"This scan is often referred to as the dating scan," says Gill Harrison, "because one of the ways that it's used is to work out your baby's due date."

When will I be offered my dating scan? Will it be at exactly 12 weeks?

All pregnant women in the UK who have informed their GP or midwife of their pregnancy or completed a self-referral maternity form (now provided as an alternative by some hospital maternity services) are offered an ultrasound scan at about the 12-week mark.

If you're in England or Wales, it will be offered at between 10 and 14 weeks; if you're in Scotland, it will be offered between 11 and 14 weeks, and in Northern Ireland, it will be offered between 8 to 12 weeks.

If you've had fertility treatment, have a history of miscarriages or are in pain or bleeding during the first weeks of pregnancy, you may be offered an early scan before this routine dating scan. But, assuming your pregnancy is confirmed as healthy at that scan, you'll still have your dating scan at round about the 12-week mark.

The 12-week scan usually takes place in a hospital local to you, and you will receive a letter or a text confirming the date, time and place.

Do I have to have the dating scan? Is it safe?

Ultrasound scans use high-frequency sound waves to capture a picture of your baby inside your womb. There are no known risks, either to you or to your baby, from having a pregnancy ultrasound scan in a professional health setting, such as the NHS.¹²³

You can, however, choose not to have any pregnancy scan, if you don't want to.⁴

What does a 12-week scan reveal?

Officially, the purpose of the scan is to check:

• How many weeks pregnant you are and when your baby is due. An ultrasound scan is a much more accurate way of predicting your baby's gestation (how far along in the pregnancy you actually are) than counting from the date of your last period (which is all you and/or your GP have had to go on until now).
• Whether you're having a single baby – or twins, triplets or more. Yep, this is the moment when you find out if there's more than one baby in there!
• If there's a heartbeat. This is the bit that, naturally, we all worry about most.
• If your baby's skull, limbs, organs, and umbilical cord are developing normally for this stage of pregnancy.
• Your baby's nuchal translucency (NT). This is a measurement of the fluid at the back of your baby's neck. This measurement is then combined with the results of a blood test (which may be done on a different day to your scan) to complete the combined screening test*, which gives an indication of your baby's chance of having Down's syndrome, Edwards' syndrome and Patau's syndrome. You can opt out of this part of the scan and, therefore, the combined screening test, if you prefer.
  * If, for whatever reason, you're having your first dating scan after 14 weeks, you won't be offered the combined screening test you but will be offered another blood test (the 'quadruple test') between 14 and 20 weeks that screens for Down's syndrome (but not Edwards' or Patau's).

What do I need to do or bring for the 12-week scan?

You may have already been given some notes or forms by your midwife; if so, bring them along.

It's best to wear loose trousers or a skirt and top, rather than a dress, because when you have your scan, you'll be asked to lie on your back on a couch and adjust your clothes to expose your belly.

You'll also be asked to arrive with a full bladder: the fluid will enhance the sound waves moving through your abdominal cavity, making the ultrasound image clearer – and your scan pictures better!

Your appointment letter may give instructions about the best way to do this but, if not, we'd suggest going for a good, bladder-emptying wee about 90 minutes before your scan appointment time and then, about an hour before, drinking 400ml to 500ml water.

Don't be tempted to skip the water-drinking because you're worried about not being able to hold in it if the scanning department is running late and you have to sit in a waiting room. As Leanne from our MadeForMums Community says, "they can always send you for a [bit of a] wee [if you're bursting] but, if your bladder's not full enough, they might send you home".

What happens at the 12-week scan?

You'll be taken into a private room, which is often quite dimly lit (so it'll probably look more like the picture below – see Will I see a picture of my baby? – than the one above). You'll then be asked to lie down on your back on the couch and adjust your clothes so that your belly is exposed.

The scan is done by moving a hand-held device called a transducer – which looks a bit like a computer mouse or a small paint roller – over your tummy. The sonographer will put some gel on the skin of your tummy first (be ready: it’s normally freezing!), so there is good contact between the transducer and your skin. Often, your sonographer will also tuck some tissues around the edges of your clothes nearest your tummy, to protect them from the gel.

Once the gel's on, the sonographer will place the transducer onto your bump and move it around, allowing the high-frequency sound waves produced by the transducer to bounce off your belly and create a picture on the sonographer's monitor.

It doesn't hurt at all but you'll probably feel some downward pressure (which can be a little uncomfortable on a very full bladder).

If your womb is sitting very deep in your pelvis or you're very overweight, your sonographer may offer you a a trans-vaginal scan instead, in order to get a better image. This type of scan uses a small, finger-width probe transducer that is inserted gently into your vagina; it can be a bit uncomfortable but shouldn't be painful.

Will I see my baby on the screen?

As the transducer gets to work, a black-and-white image of your baby will appear on the monitor that the sonographer is looking at. Often, you can see it, too, or the screen will be turned towards you after a few moments – but not always.

"Sonographers have a lot to do in a short amount of time, so they need to keep their screen in a position that gives them the best view of the baby,” explains Gill Harrison. "Hopefully, if there is no separate second screen for you to look at, you will be able to see the sonographer's screen but you need to remember that the points of this clinical examination to check everything is OK with your baby.

"All being well, you're likely to see your baby moving around. And, if the pregnancy is progressing well, you'll also see a clear heartbeat."

This was certainly the case for Fiona from our MadeForMums Community. She said:

There was a good heartbeat and the baby was really wriggly. In fact, it didn't stop for the whole scan – which was really exciting!

Can I take a picture or a video myself? If not, how do I get a picture to keep?

You're usually asked not to take your own video or photos – or record audio of the baby's heartbeat – while you're in the scan room but most NHS hospitals will let you take away a photograph of the scan image once your appointment has ended.

Costs for these vary, and aren't always flagged up in advance, so do make sure you take some cash with you (some hospitals can't accept card or phone payment).

If you're after lots of glossy colour pics or maybe even a video, you can consider booking (and paying for) a separate private scan; with these, it's best to wait till you're at least 16 weeks pregnant, when there's much more 'baby detail' to see.

How long does the 12-week scan take?

The scan itself will take about 15 to 20 minutes but you may need to hang about for a while in the waiting room beforehand – which we know can be tricky when you've just drunk all that water!

Occasionally, if the sonographer is unable to get a clear picture of what they need to see, you may be asked to come back for a repeat scan on another day.

Can I take my partner to the scan?

Your partner (or one close adult relative) will always be welcome to come with you but it's totally up to you, of course. Most mums-to-be would probably say it's a good idea to have some company, especially if you're anxious about the scan.

"Having a scan can be very emotional," says Jane Fisher, director of the testing-support charity Antenatal Results and Choices (ARC). "You may need someone there to support you."

Can I take my other children to the scan?

You'll need to check with your hospital about this one, and you should be prepared for them to say no: quite a few hospitals don't allow small children into the pregnancy ultrasound departments.

"We generally do not recommend bringing your children to the NHS screening scans," says Gill Harrison, "but the policy on this does vary from hospital to hospital. Performing the scan requires intense concentration from the sonographer, so many hospitals take the view that the fewer distractions, the better."

Will I be able to tell from the scan if my baby's a boy or a girl?

"The policy at most NHS trusts is not to give an opinion at this scan," says Gill. "That's usually only offered at the 20-week scan [your 2nd routine scan, done at about 20 weeks].

If you just can't wait till 20 weeks to find out your baby's sex, you can book a separate private 'gender reveal' scan.

Or you could have some fun predicting your baby's sex yourself, trying to spot some of the many boy/girl signs touted by various theories – usually with next to no scientific evidence. The most popular of these involve studying your 12-week scan photo for clues and include:

• The Nub theory
• The Skull Theory
• The Ramzi theory

There is also the more scientifically-sound 3 lines or Potty Shot Method but this is extremely unlikely to work on a 12-week scan photo; to use it with any reliability, you need an image from at your NHS 20-week scan or from a scan done between 16 and 23 weeks by private pregnancy-scan provider.

Will I get the results straightaway?

Pretty much – even if it's not such good news.

"If there is clearly an issue with the scan, then you will be told that day," says Gill. "And you’ll probably get an appointment to see a specialist to help you make decisions about further tests."

The only exception to the results-straightaway rule is the result of the combined screening test (if you consent to it).

In order to get the full results, the findings of the nuchal translucency (NT) part of your scan need to be combined with the findings of your blood test. If you haven't had your blood test yet (timings of these tests do vary from hospital to hospital) or if your blood test results haven't come through in time for both results to be combined into the final result, you'll have to wait to get this result from your midwife at a later date (do ask when that's likely to be).

What will the results tell me?

If all is well, and your pregnancy is progressing as it should – which is the case about 95% of the time – you will be given your official due date, or estimated date of delivery (EDD), and told exactly how pregnant you are.

You may find that your EDD is quite a few days later or earlier than you thought:

I thought was 11 weeks, 6 days when I went for my scan but they moved my due date back by 5 days as the baby was a bit smaller

You'll also be told whether you're having twins, triplets (or more) – though you'll probably have noticed that already on the scan monitor!

If your scan picks up anything of concern, this might include:

• Missed miscarriage. Very occasionally (in about 1% of pregnancies), the sonographer may not be able to detect the baby's heartbeat. This is usually because, earlier on in your pregnancy, the baby died or failed to develop but you may not have had any signs or symptoms (like pain or bleeding). If this happens to you, there are a number of possible next steps; you will be given specialist advice – and time to make up your mind.
• A developmental concern. Sometimes, the sonographer will detect an unexpected finding which may indicate a problem with your baby's development. If this happens to you, you will be referred to a fetal medicine consultant for further advice and tests.
• A raised NT measurement. You may be told on that day if your nuchal translucency test measured higher than 3.5mm. "This raised NT can sometimes be an indicator of a problem in your baby's development," explains ARC's Jane Fisher. Depending on the measurement it might need to be looked at in combination with your blood test. If there are still indications when that is done, "you will," says Jane, "be offered an appointment with a fetal medicine specialist to discuss the possible implications." Which will include the offer of further tests, including amniocentesis or CVS. "Although this can be worrying," says Jane, "it is important to remember that many babies whose NT measurement is higher than average do develop normally.”

I'm worried about this scan? Am I right to be?

It's quite normal to feel anxious – as well as excited at the idea of seeing your baby. We all do!

But it really does help to try to keep things in perspective: the chances of anything being 'wrong' with your baby are very small:

While it’s good to be prepared, be reassured that there is only an issue in around 3% to 5% of pregnancy scans

Even if there is an issue, it may well be something that turns out to be not that serious or something that can be easily managed by the specialists.

And there's always a follow-up with support and advice. "If there is a problem, you will be supported and quickly referred to a specialist," says Jane. You can also call the trained staff on the ARC helpline on 0207 713 7486 or send them a text on 07908 683004 (Monday to Friday, 10am to 5.30pm).

Above all else, remember that, for at least 95% of us, the scan will be fine and we'll go home clutching that amazing (and slightly tear-stained) first pic.

I was so worried. I was literally having an asthma attack by the time they called me in. But it was great. I saw the little heartbeat and the baby was bouncing up and down and kicking their arms and legs! It really was great – even my hubby welled up!

When will my next pregnancy ultrasound be?

Assuming all has gone well with your 12-week scan, your next pregnancy scan will be your 20-week scan, which is usually carried out at between 18 and 21 weeks.

This is generally the scan when you can find out if you're expecting a girl or a boy – assuming you want to know...

References:

<sup>1. Safety of ultrasonography in pregnancy: WHO systematic review of the literature and meta-analysis. Torloni et al. Ultrasound in Obstetrics and Gynaecology. First published 17 March 2009; doi.org/10.1002/uog.6328.
2. Warning sounded over commercial ultrasound in pregnancy. The Lancet. 3 January 2015
3. Ultrasound exams: frequently asked questions. The American College of Obstetricians and Gynaecology. Last reviewed October 2021.
4. Ultrasound scans in pregnancy. NHS online</sup>

Pics: Getty Images

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