which tests will I need?

Checking up on the health of you and your growing little one can be one of the most daunting but reassuring parts of pregnancy. Tests let you take a peek at what’s going on inside your bump, better preparing you for what’s in store.

what ultrasound tests will I have?

It all starts with the ultrasound. Seeing your baby for the very first time is an experience no one can prepare you for – while it’s incredibly exciting, we also know it can be a little scary. But if any of your scans do pick up on anything that doesn’t look quite right, you can have further tests to figure out what’s going on.

the dating scan


  • when? Between 10 and 16 weeks
  • why? This one’s the biggie – it’ll let you know when your due date is[1]
  • what else should I know? Bring a box of tissues, because it’s going to hit you harder than you might realise. For many parents, seeing your little one for the very first time is the moment it truly begins to feel real


the nuchal translucency test


  • when? Between 11 and 13 weeks (can be combined with the dating scan)
  • why? It looks for the likelihood of your baby having Down’s syndrome by measuring the fluid behind the neck[2] (babies with Down’s syndrome have more of this)
  • what else should I know? This test isn’t available in all NHS regions and might need to be combined with the diagnostic tests we talk you through further down


the anomaly or mid-pregnancy scan


  • when? Between 18 and 24 weeks, when your baby’s starting to look like a little person
  • why? It checks the brain, heart, kidneys, liver and spine and measures your baby
  • what else should I know? If you’ve decided you want to know whether you’ll be bringing a little boy or girl into the world, now’s the time to ask. Some hospitals do have a policy of not revealing this, so be sure to check with your sonographer


Having your first test is definitely nerve-racking, but the good news is you’ll go through the exact same procedure for your future ultrasounds. You’ll lie down, then the sonographer will apply gel to your stomach to help the probe move over your skin. When the sonographer passes the probe across your stomach, the ultrasound waves it sends out are picked up on the screen. That’s what gives you that grainy but oh so exciting first glimpse at your child.

Our final good-to-know? Drink up before you go for your ultrasounds. While it might not feel the most comfortable, having a full bladder will give you a much clearer picture.

will I need any risk or diagnostic tests?

We know how hard it is to even begin imagining your little one having any health problems. But if your ultrasounds do pick up on anything, there are tests that’ll give you more certainty and help you decide how to move forwards. And it’s completely up to you whether you choose to have them done or not.

There are two types: risk and diagnostic tests. Here’s what they do and the order you’d have them in.

what are risk tests?

Doctors use these ones to work out how likely your baby is to develop certain conditions.

To give an initial risk indicator, your nuchal translucency results will be combined with your age. You can choose to have a more accurate ‘combined test’ – this one involves a blood test. You’ll also be given a risk level for two syndromes that aren’t so well known: Edward’s and Patau’s.

Another one to know about is the ‘mouthwash test’. If you or your partner’s family has any history of cystic fibrosis, this test can show if either of you carry the gene. If that’s the case, a specialist genetic counsellor will be on hand to talk you through what this means.

will I need a diagnostic test?

If you do have high risk levels or a family history of certain conditions, you can choose to take one of these. As ever, this is entirely up to you.

the CVS test (chronic villus sampling)


  • when? Between 11 and 14 weeks
  • how? A thin needle is passed through your stomach into your placenta (guided by ultrasound), where cells are taken for analysis
  • what else should I know? It has a 1-2% risk of miscarriage, but will give you an earlier result than an amniocentesis test


the amniocentesis test


  • when? After 15 weeks
  • how? Again, a needle is inserted through your abdomen with an ultrasound guide, this time to collect a sample of amniotic fluid
  • what else should I know? The risk of miscarriage is less than with the CVS test (1%), but the test will happen later in your pregnancy


These tests might sound a little alarming, even to mums who’ve been through pregnancy before. Just remember that in most cases, they’ll show a healthy baby and give you some much-needed peace of mind. And if there are any problems, you’ll be surrounded by professionals who can give you all the information you need to make the right decision for you.


[1]. 12-week pregnancy dating scan, NHS, December 2017

[2]. Nuchal Translucency Screening, What to Expect, April 2019