About the Anomaly Scan

20 weeks

The purpose of an Anomaly Scan is to check development of the baby and is normally performed at around 20 weeks.

When you attend for this scan we will assume that you wish to know about all problems that are detected by the scan and any concerns that result.

Most anomaly scans are carried out trans-abdominally (through the tummy) with an abdominal probe. A full bladder is helpful for this type of scan. Sometimes, we may need to perform the scan through the vagina if your baby’s head is low in your tummy in order to check the developing brain.

The Anomaly Scan will usually identify:

• about 99% of babies with conditions like spina bifida
• about 50% of babies with major heart defects
• about 70% of all serious congenital malformations
• a low lying placenta (placenta praevia)
• a blood vessel which overlies the placenta (vasa praevia) which is rare but can cause lethal bleeding in labour and is not part of your NHS scan
• some, but not all, babies with bone growth problems (skeletal dysplasias)
• gender (sex of baby) is optional

It cannot detect cerebral palsy, autism and learning problems.

It’s also important to know that some problems may develop later in your pregnancy and so won’t be seen on the anomaly scan, for example a diaphragmatic hernia.

During the scan, we check the development of the following organs or movements: head, brain, face, spine, arms, hands, fingers, heart, lungs, bowels, kidneys, bladder, legs, feet, the fluid around the baby, the umbilical cord and position of the placenta.

The ability to check your baby’s development can be affected by factors such as the body weight of the mother or how your baby is lying in the womb. Sometimes, it is not possible to see full views of a certain part of the baby’s body and if this happens, we’ll invite you back for a repeat scan. This happens in about 10% of cases so please don’t be worried if this happens to you. You’ll only be charged once no matter how many times we need to bring you back.

After your scan, you will receive a text link to our Tricefy Baby Scan Photo Service so that you can download and share your images.

All of our growth scans are undertaken by fully qualified, regulated and insured sonographers who are all also senior sonographers within the NHS.

Should a problem or concern be identified, they will contact a Consultant Clinician on the same day as your scan. You won’t have to be referred elsewhere and your imaging will be reviewed quickly by the most senior fetal medicine expert in Wales.