The nuchal scan is the standard first-trimester screening scan in the UK. It measures a small pocket of fluid behind your baby’s neck, called the nuchal translucency, and allows the doctor to estimate the risk of certain chromosomal conditions, including Down’s syndrome. It also allows a much closer look at your baby’s developing anatomy than was possible at viability scans.
When does the nuchal scan happen?
The nuchal scan is performed at 11-13 weeks of pregnancy. The window is precise: the nuchal translucency measurement is only valid between 11 weeks and 13 weeks 6 days, so timing matters.
What is the nuchal scan for?
The purpose of a nuchal scan is to:
- Date the pregnancy
- Allow the operator to measure the volume of translucent fluid in the space behind your baby’s neck, thereby estimating your baby’s risk of having chromosomal abnormalities such as Downs Syndrome, Edwards, Patau and Turner Syndrome
- Determine whether more diagnostic testing, such as NIPT, CVS or Amniocentesis is necessary
- Examine your baby’s heart in greater detail
What the result actually means
The nuchal scan is a screening test, not a diagnostic test. It produces a probability, such as a 1 in 5,000 chance, not a yes/no answer. Most parents are reassured by a low-risk result. Where the result is higher-risk, the next step is usually a non-invasive prenatal test (NIPT) or, less commonly, diagnostic testing such as CVS or amniocentesis to give a definitive answer. Dr Duncan will discuss your options with you in detail at the appointment if needed.
Dr Duncan offers NIPT directly, with results usually available within 48 hours. NIPT costs £500.
NIPT is included in Dr Duncan's fixed price private maternity care package from 6 weeks.
What happens during my appointment?
The scan is painless as ultrasound uses sound waves only, with no radiation, so is safe for both you and your baby.
You will lie comfortably on the examination couch, and a small amount of water-based gel is applied to your abdomen so the probe can move smoothly across the skin. You will see the live images on the screen as the scan progresses, and Dr Duncan talks through what he is looking at as he goes. The bloods are drawn at the same appointment.
What happens if the result is higher-risk?
If the combined result is higher-risk, Dr Duncan will discuss the options with you fully at the same appointment, including NIPT and, where appropriate, diagnostic options like CVS or amniocentesis. Dr Duncan is a sub-specialist in maternal and fetal medicine, and most early-pregnancy findings can be assessed and explained on the spot, with any further investigations arranged from there.
Booking your nuchal scan
To book a nuchal scan, please contact the practice or book online. Because of the strict 11-13 week window, please book early in your pregnancy to secure a slot at the right gestation.
The fee for a standalone nuchal scan and antenatal consultation is outlined on Dr Duncan's fees page.
For a fuller picture of all the scans available through pregnancy, see Ultrasound Baby Scans.