Down Syndrome 12-Week Scan (First-Trimester Screening)

The Down Syndrome 12-Week Scan is a specialised early-pregnancy ultrasound that provides essential measurements used to assess the risk of Trisomy 21 (Down syndrome) and other chromosomal conditions during the first trimester.

This scan is performed between 11 weeks + 2 days and 14 weeks + 1 day, the precise biological window in which these measurements are clinically valid.

Our clinic performs the ultrasound portion of the assessment and works in partnership with The Doctors Laboratory (TDL), who complete the Down Syndrome Risk Profile (1st Trimester) blood test and produce the final risk calculation.

What This Scan Includes

During your 30-minute consultation, our clinicians complete a focused ultrasound assessment covering the four key fetal measurements required by TDL:

1. Nuchal Translucency (NT)

Measurement of the fluid behind the baby’s neck — a crucial marker for first-trimester screening.

2. Crown–Rump Length (CRL)

Confirms gestational age and eligibility for screening.

3. Head Circumference (HC)

Assesses fetal growth and supports accurate biometric analysis.

4. Biparietal Diameter (BPD)

Measurement of the width of the baby’s head, used for dating and screening accuracy.

All images are printed or digitally shared as needed.

Partnership With The Doctors Laboratory (TDL)

During your consultation, we complete all necessary TDL forms, including:

• Maternal Screening Request Form
• Down Syndrome Risk Profile Blood Test Request Form
• Ultrasound Measurement Sheet (NT, CRL, HC, BPD + images)

You will then attend a TDL location of your choice for the blood test.

Your Patient Journey

Step 1 — 30-Minute Scan at Our Clinic (£180)

• Ultrasound and measurements
• Printed or digital images
• Completion of all TDL documents
• Explanation of the next steps

Step 2 — Attend TDL With 3 Documents (£223)

• Maternal Screening Request Form
• Blood Test Request Form
• Ultrasound images and measurement sheet

Step 3 — Final Risk Calculation

TDL performs the blood test and issues the official first-trimester Down Syndrome Risk Profile.

Patient FAQs

What is the purpose of this scan?

To provide accurate ultrasound data used in calculating the risk of Down syndrome and other chromosomal conditions during the first trimester.

Is this a diagnostic test?

No — it is a screening process. If results indicate higher risk, further diagnostic testing (NIPT, CVS, or amniocentesis) may be offered.

Does this scan look at the whole baby?

It is a focused assessment targeting the four measurements required for the screening profile. More detailed anomaly scans occur at 20 weeks.

Do I get results on the day?

You receive your measurements immediately. The risk calculation comes from TDL after they process your blood sample in around 5 dyas.

Do I need full bladder preparation?

At 12 weeks, a moderately filled bladder helps with imaging, but no strict preparation is required.