An anatomy scan is a detailed mid-pregnancy ultrasound that checks your baby’s organs, growth, placenta, umbilical cord and amniotic fluid.

When is the anatomy scan?
The anatomy scan is usually performed between 21 and 22 weeks and is considered a Level II (detailed) ultrasound.

What to expect
Your sonographer will take a series of measurements to check that your baby is growing as expected and to assess key structures.

Finding out the baby’s sex
If you’d like to know, the sonographer can often determine the baby’s sex at this scan. This isn’t guaranteed—it depends on the baby’s position and the clarity of the image on the day.

An anatomy scan usually takes 30–45 minutes, depending on your baby’s position and movement on the day.

A Level II ultrasound is a detailed fetal anatomy scan. It provides an in-depth evaluation of your baby’s anatomy and development and typically takes 30–45 minutes.

At your anatomy survey scan, your sonographer will:

• Confirm your baby’s position.

• Identify the placental location.

• Assess the amount of amniotic fluid.

• Measure your baby’s growth and compare it with the expected range.

About this scan
Also known as the routine or anatomy scan, this appointment provides a detailed check of your baby’s anatomy and is carried out between 21 and 22 weeks of pregnancy.

Before you arrive
Please do not empty your bladder just before the scan, as a comfortably full bladder can improve image quality.

When you arrive
If this is your first visit to Merrion Ultrasound, you’ll be asked to complete a short registration form at reception. You’ll then wait in the lounge until your sonographer calls you.

During the scan
Your sonographer will confirm your details and then perform the ultrasound. Much of what they examine won’t be obvious on the screen, as they are focusing on specific anatomical structures. They will check your baby’s face, spine, abdominal wall, heart, stomach, kidneys, arms, legs, hands, and feet. They will also take standard measurements, including head circumference, abdominal circumference, and femur length.

In addition to assessing growth, your sonographer will review the placenta, umbilical cord, and amniotic fluid.

After the scan
Our aim is to make your visit as relaxing as possible. We welcome questions at any time, so please don’t hesitate to ask your sonographer.

From around 19 weeks, it’s sometimes possible to determine the baby’s sex on ultrasound, but it isn’t guaranteed. The baby’s position may not allow a clear view of the genital area. If you’d like us to look, please tell your sonographer at the start of your appointment. Even with the best images, sex determination depends on the baby’s position and movement, so occasionally it’s not possible on the day.

If we see anything concerning during your scan, we’ll explain it to you straight away. In some cases, we may ask you to return for additional images and a consultation with one of our fetal medicine specialists. If the matter is urgent, this is usually organised within 24 hours.

Most repeat scans are not due to serious problems—many are simply because the baby’s position or movement makes it hard to get clear views. Around 15% of scans need a repeat for one reason or another.

At the end of your appointment, you’ll receive images of your baby and a detailed report of the findings. With your consent, we can send a copy of the report to your obstetrician and/or GP.

To book an Anatomy Survey Scan, please call (01) 637 4060 or use the Make a Booking form. This scan is performed from 21 to 22 weeks. Merrion Ultrasound, located in Dublin 2, provides ultrasound for all stages of pregnancy—including early pregnancy, nuchal translucency, anatomy, and growth scans—and is open to all patients, not only those attending the National Maternity Hospital.

As this is a medical examination, we kindly ask that children do not attend. Thank you for your understanding.

You can book directly—Merrion Ultrasound provides scans for all patients, not only those attending the National Maternity Hospital.

This scan is scheduled at 21–22 weeks of pregnancy.

Typically 30–45 minutes, depending on your baby’s position and movement on the day.

Please don’t empty your bladder just before the scan; a comfortably full bladder can improve image quality. Wear a two-piece outfit if possible to make it easier to expose your abdomen.

Your sonographer reviews your baby’s brain, face, spine, heart, stomach, kidneys, abdominal wall, arms, legs, hands and feet; measures growth; and also checks the placenta, umbilical cord, and amniotic fluid.

The scan can show signs of some rare conditions (for example, spina bifida, anencephaly, certain abdominal wall and kidney problems, and some heart problems), but no scan can detect every condition.

Yes—diagnostic ultrasound has no known harmful effects at standard settings and is the imaging method of choice during pregnancy.

About 15% of scans need a repeat because the baby’s position or movement limits what can be seen. A repeat scan doesn’t automatically mean there’s a problem.

Often yes—if you’d like to know and the view is clear—but it isn’t guaranteed if the baby’s position doesn’t allow it. Please tell your sonographer at the start.

We’ll explain findings at the visit. You may be invited back for additional images and, if needed, a consultation with a fetal medicine specialist—usually arranged within 24 hours when urgent. You’ll receive images and a detailed report and if you consent, we can send a copy to your obstetrician and/or GP.

It isn’t painful, though you might feel gentle pressure from the probe to obtain the best views. Ultrasound uses sound waves—not radiation—and is considered safe in pregnancy.

Yes—photos and a computerised report are included, and your sonographer will answer any questions you have.