Anomaly Scan - 20 Week Scan - Anatomy Survey Scan

This 20 week scan consists of a full anatomical survey and includes photographs and a computer print out of details obtained. The placenta will be localised and measurements of your baby will be performed to ensure that it is growing normally.

The majority of babies are healthy at birth, but unfortunately about 2-3% of babies are born with a birth defect.   About half of these major defects will be seen on a scan and half will not be detected during pregnancy.  This means that even if your scan is apparently normal, there is a small chance that your baby may still have a problem because ultrasounds have limitations.

Anomaly Survey Scan - What to expect at Women’s Health Group

An anomaly scan is often referred to as “the twenty week scan” or “the detailed scan”.  It is normally performed between 21 - 24 weeks gestation as this is the best opportunity during pregnancy to examine all the anatomy of your baby in great detail.   It is not necessary for you to have a full bladder for this scan. The anatomy or 20 week scan is a transabdominal scan and is non-invasive procedure.

When you arrive at Women’s Health group you will be greeted by a member of our administration team.  It is likely that you may have previously attended Women’s Health Group for an early dating pregnancy scan but if this is your first time with us you will be given a registration form to complete. You will then be directed to our waiting area where you will await your sonographer.

Your sonographer will meet you in the waiting area and take you to the ultrasound room.   They will confirm your details before the ultrasound procedure begins.

The sonographer will spend the majority of the time looking at various anatomical details of the baby that are not obvious to you but the sonographer will explain what you are looking at as they scan your baby.   It is our aim to make your visit with us as relaxing and as stress free as possible so if you have any queries please do not hesitate to ask your sonographer.

The sonographer will check all your baby’s organs and take measurements and images.   She will check your baby’s face, baby’s spine, baby’s abdominal wall, baby’s heart, kidneys and stomach.   Your baby’s arms legs, hands and feet will also be checked.  Measurements of the baby’s head circumference, abdominal circumference and femur will be taken.

As well as checking the how your baby is growing the sonographer will check the placenta, the umbilical cord and the amniotic fluid.

It is sometimes possible to tell the sex of the baby at this scan, but not always.   If you wish to know the gender of your baby please inform your sonographer at beginning of your ultrasound.  However, determining the sex of the baby is not always easy and it can depend on position of the baby in the uterus.   Baby needs to be in a favourable position to visualise the genital area and the baby does not always oblige.

If at the time of scan a problem is suspected, you will be told at that stage that there may be a problem.  A full discussion of the problem may require you to be reviewed by a fetal medicine specialists.  This can usually be organised within 24 hours if the problem is deemed urgent.  Most problems that need repeat scanning are not serious and approximately 15% of scans will need to be repeated of one reason or another.

At the end of your anomaly scan you will be given images of your baby and a detailed report on the findings of your scan.