What to Expect at Your 20-Week Scan (Anomaly Scan)

Maria Birch

02 Jul 2025 — 3 min read

By Maria Birch, UK-Registered Obstetric Sonographer

If you’re approaching the halfway point in your pregnancy, chances are you’re feeling a mix of excitement and nerves about your 20-week scan—also called the anomaly scan or mid-pregnancy ultrasound.

As a sonographer (and mum of two), I’ve performed thousands of these scans—and recently experienced one myself during my second pregnancy with Baby Birch.

So in this post, I want to walk you through:

What actually happens at the 20-week scan
Why your baby’s position can make things tricky
What happens if the sonographer can’t see everything
And what to do if you leave feeling disappointed, confused, or anxious

My 20-Week Scan Experience: A Tale of a Very Sleepy Baby

When I had my own 20-week scan for baby number two, it didn’t quite go to plan!

Just an hour before the appointment, baby was bouncing around non-stop. But by the time we arrived, he had curled up in a tight little ball and fallen fast asleep, head tucked down and back facing outward.

From a scanning perspective, that’s about as awkward as it gets. My lovely colleague—who also happened to be a former teammate—had her work cut out for her.

But she did an incredible job. Even though Baby Birch wasn’t making things easy, she managed to carefully check his brain, heart, spine, kidneys, limbs, and everything else the scan is designed to assess.

And most importantly, everything looked healthy and normal.

That moment—seeing his heart beating, organs forming, limbs stretching—was full of quiet relief and joy. I left feeling deeply reassured.

But I also left without any scan photos.

Because baby never moved into a good position, there just wasn’t a clear image to capture. No profile shot. No tiny feet. No sweet yawn frozen in time.

What Happens If Your Baby Is in a Difficult Position?

It’s surprisingly common for babies to be uncooperative at the anomaly scan.

Whether they’re curled up, tucked into the placenta, lying low, or simply fast asleep, it can sometimes be hard to get a good view—especially if you’re being scanned on a tight schedule.

If this happens, your sonographer will try different techniques: asking you to roll over, walk around, or come back later in the day. But sometimes, despite best efforts, not all views are possible on the day.

In most NHS settings, if something essential can’t be seen, you’ll be invited back for a repeat scan. But if your baby is healthy and measurements are complete, the scan is considered clinically successful—even if you didn’t get clear pictures or much time to take it all in.

And that’s where some parents leave feeling a little… deflated.

What the 20-Week Scan Is (and What It Isn’t)

The primary purpose of the 20-week anomaly scan is medical. It’s a detailed screening to check how your baby is developing and to identify any structural abnormalities early on.

It is not:

Designed for bonding
Focused on capturing keepsake images or video
Intended to offer a long explanation of what you’re seeing
Guaranteed to provide a photo or printout

That doesn’t make it less important. But it can leave some parents wanting more—especially when it’s their first time seeing baby clearly on screen.

Want More Than Just a Health Check?

If your 20-week scan left you with unanswered questions, no images to take home, or just a lingering feeling that it was over too quickly—you’re not alone.

Many parents choose to follow up their anomaly scan with a private reassurance scan or 4D baby scan for exactly this reason. These appointments are built to give you:

More time
More explanation
The chance to ask anything
Photos and video to keep
And the chance to really connect with what you’re seeing on screen

At Sneak-A-Peek Ultrasound, we offer private scans tailored to fill the gaps left by standard NHS appointments. You’ll never be rushed. You’ll always be supported. And if baby is feeling camera-shy, we’ll do our best to work around it.

📖 Learn more about our gender scans and 4D bonding scans

Not in North Devon? Still Have Questions?

If you’re not based near Barnstaple—or you’re simply looking for expert scan guidance or reassurance without booking another in-person appointment—you can still get support.

Over at The Scan Lady, I help women around the world understand their scans, plan their pregnancy journey, and get calm, clear answers to their most worrying scan-related questions.

You’ll find: