Ultrasound scans use sound waves (which cannot be heard by the human ear) to assess the growth and development of your baby during pregnancy. During the procedure a scanning probe is passed over your tummy after the application of contact gel and an image of your baby is shown on a monitor screen. Ultrasound scanning in pregnancy has been used for many years and there are no known side effects or risks.
Your first ultrasound scan
There are two types of examination available and you can choose which type of first scan you would prefer. An explanation of each type of scan is given below 1) Dating scan This scan is performed at about 12 weeks of pregnancy. It determines the number of babies in your womb and measures your baby’s size to confirm your due date. It is not possible to tell your baby’s sex at this stage. If any problems are identified, you will be referred, the same day, to see a specialist midwife or doctor for further explanation and discussion. The scan takes approximately 15 minutes and can be undertaken at Royal Preston Hospital or Chorley Birth Centre. 2) Combined Screening Test At the same time as your dating scan you may also choose to have the combined screening test for Downs’ syndrome. Down’s Syndrome is a chromosome abnormality that causes learning difficulties and some other health problems. A full explanation of this condition can be found in the leaflet Screening tests for you and your baby that your midwife will already have given you. During this test, a dating scan is performed with an additional measurement of the amount of fluid at the back of your baby’s neck (nuchal thickness). A sample of blood is taken from you and sent to the laboratory for an assessment of substances that are passed into your blood from your baby. Together, the blood test result and 3
the nuchal thickness measurement are used to calculate the risk of your baby being affected by Downs’ syndrome. The test will not give you a “yes or no” answer but will tell you if this risk is low or high. If the risk is high you would be offered further testing to determine definitely whether your baby has Down’s syndrome. The combined test can only be performed between 11 weeks and 2 days and 14 weeks 1day. It takes approximately 30 minutes and can only be performed at Royal Preston Hospital Occasionally there are difficulties obtaining a nuchal thickness measurement by abdominal scan and you would then be offered a transvaginal scan (the scanning probe is placed in the vagina). If the measurement still cannot be made, your midwife will discuss alternative methods of Downs’ syndrome screening with you.
Your results
You will not be given the combined test result on the day of your scan. A low risk result will be sent by post within 10 working days. If your result shows a high risk, a specialist midwife will contact you with your result within 4 working days of your test.
Making your choice
You can choose not to have any ultrasound scans during your pregnancy although ultrasound scanning can be a very helpful part of your pregnancy care. If you choose to have the combined test you should consider what your reactions would be to a high risk result. The further testing necessary to confirm a diagnosis of Downs syndrome carries an increased risk of miscarriage which you may feel is unacceptable. Your midwife can discuss and explain all these issues to you and you can find more information in the leaflet Screening tests for you and your baby.
When you have made your choice
If you wish to have either the dating scan or the combined test, please telephone the Ultrasound department on 01772 4
524426 between 9am – 3.30pm Monday to Friday to make your appointment. You will not be sent an appointment automatically. We need to know at this time which scan you would like to have. You will not be able to change the test you have chosen on the day of your scan because of the time allocation made for your appointment.
Preparation for your scan
One hour before your appointment please drink at least 1.5 pints of water so that you have a full bladder for your scan. Remember not to empty your bladder until after your scan. This raises your baby from a position behind your pelvic bones. An empty bladder may result in unnecessary waiting time and being able to complete your scan (particularly the combined screening test).
Can I bring a friend or relative?
As time and space is limited we can only permit one adult to attend the examination. Children are welcome to attend the dating scan but if you choose to have the combined screening test it is advisable not to attend with young children due to the length of the examination.
Photographs of your baby
Ultrasound pictures of your baby are available at a cost of £4.00** each, payment for these is via a ticket machine. Please bring the correct money and do not purchase your tickets until after the scan as photographs are not always possible and refunds cannot be given. Please let the radiographer know how many pictures you would like during the scan as once the scan is complete scan pictures cannot be printed. Please note that patients and visitors are not allowed to photograph or video scans. ** Please note this charge is correct at time of printing; current prices can be checked with the receptionist when booking your scan apppointment. 5
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Sources of further information www.lancsteachinghospitals.nhs.uk www.nhsdirect.nhs.uk www.patient.co.uk www.screening.nhs.uk
Lancashire Teaching Hospitals NHS Foundation Trust is not responsible for the content of external internet sites. Please ask if you would like help in understanding this information. This information can be made available in large print and in other languages.
Division: Women’s Health Directorate: Specialist Services Production date: Sept 2013 Review date: Sept 2016 LTHTR/Tr/2013september/41
