This information leaflet has been produced by Gateshead Health NHS Foundation Trust Maternity Unit to provide information to pregnant women who are referred for an Anomaly scan.
Purpose of the Anomaly scan
The anomaly scan is commonly referred to as the ’20 week scan’. It can take place between 18 and 22+6 weeks of pregnancy but is usually arranged at approximately 20+6 weeks gestation. The scan itself lasts approximately 30 minutes. Ultrasound waves are used to carry out the scan and there are no known risks to you or the baby. The scan is primarily to screen for 11 different conditions with your baby but cannot detect everything.
Preparing for your Anomaly scan
We ask you to come for your anomaly scan with a full bladder. You should drink a pint of water approximately an hour before your appointment time.
Please also remove any belly button bars or rings as these may damage the ultrasound equipment.
You may bring a support person to the scan appointment who can come into the exam room with you. We ask you do not bring children to the hospital unless absolutely necessary. Your support person may be asked to wait outside with the child if this situation occurs.
Performing the Anomaly scan
The scan will be performed in a dimly lit room and you will be asked to lie on a flat couch. You will be asked to move your trousers or skirt down onto your hips and tissue will be tucked in to protect your clothes. Clear (perhaps cold) ultrasound gel will then be applied and the sonographer will commence the exam.
To get optimum views of your baby, a slight pressure may have to be applied. The sonographer will be concentrating and usually quite quiet throughout. The exam usually takes the full 30 minutes as there is a vast amount of anatomy to image.
To get good quality images it may be necessary for you to get up, move your hips or empty your bladder. In some cases you could be asked to go for a walk and return for a second attempt.
During the Anomaly scan
This scan is likely to be the lengthiest one you will have. During the scan these things will be looked at in detail and images taken:
- Measurements of head, abdomen and femur (the bone of the thigh) length which generate an estimated fetal weight of your baby at that time
- Baby’s brain, face, lips, nose, arms, hands, heart, diaphragm, stomach, cord insertion, kidneys, bladder, legs, feet and spine are observed.
- The position of your placenta is observed
- The amount of fluid around your baby is observed
This anatomy is observed to detect 11 physical conditions that are screened for at the anomaly scan. More information about these conditions can be found within the ‘Screening tests for you and your baby’ leaflet online or on your BadgerNotes app.
As this is a screening exam it means these conditions are not always detected and the rate of detection varies between them. For example, Spina Bifida can usually be seen clearly on scan and 9 out of 10 (90%) are noted at this stage, however, other conditions such as heart defects are more difficult to see and about half (50%) will be detected.
In most cases the scan will show your baby appears to be developing as expected and the sonographer will inform you of this at the end. If there are any abnormalities suspected this will also be explained and you will likely be referred to Fetal Medicine Department for another scan, a discussion of the findings and a diagnosis.
The sonographer will also inform you of the position of your placenta and what this means for your pregnancy.
Your scan report should be uploaded to your BadgerNotes a few hours after your appointment.
Useful sources of information
- The 20 week screening scan: https://www.gov.uk/government/publications/fetal-anomaly-screening-programme-handbook/20-week-screening-scan
- Screening tests for you and your baby: https://www.gov.uk/government/publications/screening-tests-for-you-and-your-baby
- 20 week scan: https://www.nhs.uk/pregnancy/your-pregnancy-care/20-week-scan/
- Tommy’s PregnancyLine: 0800 0147 800
- Bliss (for babies born premature or sick) www.bliss.org.uk
- Support email: [email protected]
At the Queen Elizabeth Hospital Maternity Unit, we advocate a shared decision making approach to all decisions made by our patients. This leaflet aims to give you additional information and to act as a point of reference following a discussion with your obstetrician or midwife. If you are asked to make a decision about your own care, please make sure you have asked all the questions you need to ask and are given the appropriate time to do so. Some questions you might want to ask could be;
- What are my options?
- What are the pros and cons of each option?
- Who will support me making the decision that is the right one for me?
Contact number
If you have additional queries, particularly regarding the appointment time please contact:
Women’s Health Clinic: 0191 445 2742 (08:30-16:30)
Pregnancy Assessment Unit: 0191 445 2764 (24 hours)