Dating/Nuchal Translucency Scan
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What will happen during the scan?
The Sonographer will measure your baby from head to bottom, known as the Crown Rump Length (CRL). This is used to calculate the estimated date of delivery (EDD). The scan will also perform a basic check on your baby’s anatomy including the head and brain, abdomen, arms and legs.
Safety of the scan
Ultrasound uses high frequency sound waves to produce an image. There are no known risks to you or your baby from having an ultrasound scan.
What is the NT measurement?
This measurement is taken as part of a combined screening test, along with a blood test, which aids in the assessment of Downs (Trisomy 21), Edwards (Trisomy 18) and Patau’s syndromes (Trisomy 13). This screening test can tell you what the chance is of your baby having any of these three conditions. It will not tell you if they have the condition. This test is your choice, and not compulsory.
All babies have a small amount of fluid under the skin at the back of baby’s neck, this is called the nuchal translucency (NT). This collection of fluid is measured between 11+2 and 14+1 weeks of pregnancy.
It is important that your GP/Midwife has discussed combined screening with you prior to the scan appointment, this is so you are able to make an informed decision. If you require an interpreter, please let the scan department know before you attend.
Preparation
Please attend the appointment with a comfortably full bladder and your maternity notes.
The scan
To get clear views of your baby, the scan is performed in a dimly lit room and usually takes around 30 minutes (longer for multiple pregnancies). You will be asked to lie on a couch and ultrasound gel applied to your tummy. The Sonographer moves a handheld device called a probe over your tummy to carefully examine the baby. In some cases, a transvaginal scan may be required to see in more detail. Having the scan does not hurt, but the sonographer might need to apply slight pressure to get clear views of your baby. This might be uncomfortable. A black and white picture of your baby will then be seen on the ultrasound screen.
During the scan, the Sonographer may tell you they will be quiet for a few minutes. It is important for them to be able to concentrate so they can perform a good quality scan.
What happens if the NT measurement cannot be achieved?
Sometimes the Sonographer is not able to clearly see the NT due to the baby lying in a difficult position, or because you are above average weight. If this happens, you may be offered a different screening test- Quadruple test, which screens for Down’s Syndrome only. This will be explained and offered to you on the day if applicable.
You will also be offered a further scan between 18+0 and 20+6 weeks of pregnancy called the anomaly scan which looks for 11 physical conditions.
What will happen if a problem is found or suspected during the scan?
Occasionally the sonographer may suspect a problem during your scan. If this happens, they will explain what they have seen and may seek a second opinion from another sonographer and/or refer you to the Fetal Medicine Team.
Can I bring my family with me for the scan?
We welcome one accompanying adult into the scan room to support you.
Please note we do not allow children into the scan room, unless in exceptional circumstances arranged through your midwife, prior to your attendance. If you do need to bring children with you to your appointment, please ensure a responsible adult is with you to look after them whilst you are having your scan as they cannot be left in the waiting room unattended.
Frequently asked questions (FAQs)
- Can I have a picture of my baby?
- We are happy to provide photos of your baby. There is a small charge for this- £3 for a thermal paper photo and £5 for a glossy print.
- Can I record the scan?
- No recording equipment, including mobile phones or electronic devices (audio or visual) are permitted during the ultrasound examination.
Further information
We kindly ask for your understanding regarding the importance of appointment slots. If you are unable to attend your scheduled scan appointment, please contact us as soon as possible. This will enable us to reallocate the appointment to another patient.
Obstetric Ultrasound Reception: 01908 995402 (Monday-Friday 9am-4:30pm)
E-mail: [email protected] (non-urgent)
Antenatal and Newborn Screening Co-ordinator- 01908 995236
Please be aware that anonymised images from your examination may be used for teaching purposes. Please inform the department if you do not wish your images to be.
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