The Scan Room Dictionary: Plain-English Translations for Parents Who Left Their Medical Hat at Home

You are lying on the scan bed, gel on your tummy, screen glowing beside you, and someone says something like: “The CRL puts you at twelve plus four, EDD stays the same, and presentation is irrelevant at this stage.” It is a lot to take in when all you really want to know is whether everything looks okay.

Scan rooms have their own shorthand. None of it is designed to exclude you. It is simply the everyday language of people who measure babies all day. Still, a little translation goes a long way towards feeling like a participant rather than a spectator. Here is a gentle glossary for the car journey home.

Why scan language can feel like a code

Private pregnancy scans are usually reassuring, calm appointments. But the sonographer is often thinking out loud, typing notes, and moving through a checklist at the same time. Add in the emotion of seeing your baby and it is completely normal for words to wash over you.

At Peek-a-Boo Baby Scan, we think the best appointments are the ones where you feel able to say, “Sorry, what does that mean?” Nobody expects you to arrive with a medical dictionary. This guide is simply a starting point.

The everyday words you are likely to hear

Sonographer. The person carrying out your scan. They are trained to take images and measurements, and they will usually explain what they are checking. They are not usually there to give you a diagnosis, but they can tell you what they see on the screen.

Viability. In early pregnancy, this generally means the scan has confirmed a pregnancy developing in the womb, with signs such as a heartbeat or a measurement that matches your dates. It is a routine word in early scans, though it can sound more dramatic than it feels in the room.

CRL, or crown-rump length. This is the measurement from the top of the baby’s head to the bottom of their bottom in early pregnancy. It is one of the most common ways to date a pregnancy before the second trimester. If you hear CRL, they are usually working out gestational age.

EDD, or estimated due date. Not a deadline, despite how it sounds. It is an estimate based on your dates and measurements. Many parents find it kinder to think of it as a due month rather than a due day.

GA, or gestational age. How far along the pregnancy is, usually written in weeks and days. So “12 plus 4” means twelve weeks and four days.

Presentation. How the baby is lying — for example head-down, breech, or sideways. At an early scan this is often irrelevant because babies move constantly. Later on, it becomes more useful information.

Placenta position. Where the placenta is sitting in the womb, such as anterior, posterior, or low. An anterior placenta is simply at the front; you may hear it described as a normal variation. A low-lying placenta may need a follow-up scan later, so it is worth asking what happens next if that phrase comes up.

AFI, or amniotic fluid index. A way of assessing the fluid around the baby. You are more likely to hear this in later pregnancy or growth scans than in a straightforward early reassurance scan.

The measurement initials explained

Second-trimester and growth scans often use a cluster of abbreviations. None of them are secret, but they do arrive thick and fast.

• BPD — biparietal diameter, a measurement across the baby’s head.
• HC — head circumference, the distance around the head.
• AC — abdominal circumference, the distance around the tummy.
• FL — femur length, the length of the thigh bone.
• EFW — estimated fetal weight, an educated guess based on measurements rather than a weighing scale.

These help build a picture of growth. A single measurement is rarely the whole story, and scans are not perfectly precise. If numbers are mentioned, it is fair to ask whether they are within the expected range and whether anything needs checking again.

Phrases that are usually routine

Some scan-room language sounds more alarming than it is. “The baby is measuring a little ahead” or “a little behind” is common and often simply reflects normal variation or the limits of scan measurements. “Anterior placenta” is usually just a location. “We could not get a clear view” is frustrating, but it is not automatically bad news; babies wriggle, curl up, and hide behind their hands.

You may also hear that a private scan is not a diagnostic anomaly scan. This is an honest boundary, not a brush-off. Private reassurance scans can check growth, heartbeat, position, and wellbeing, but they do not replace the NHS anomaly scan or other routine care.

When it is worth asking a follow-up question

If you hear words like borderline, complex, below the expected range, low-lying, needs reviewing, or I would like to discuss this with you, pause and ask for plain English. You are not being difficult. You are being a parent.

It is also reasonable to ask if a finding needs to be shared with your midwife or GP, and whether the clinic will provide a written report. A good private scan should leave you with a clear next step, even if that next step is simply “no action needed.”

Questions to ask before you leave

1. Can you explain that word in plain English?
2. Is this a routine finding or something that needs follow-up?
3. Will this be written in my report, and who should see it?
4. Do I need to tell my midwife or GP?
5. Are the measurements within the expected range for this stage?
6. If I am unsure later, who can I contact?

You do not need to memorise the glossary. You just need permission to ask. A calm scan is not one where you understand every abbreviation — it is one where you feel able to say when you do not. And that is always a question worth asking.