What This Scan Includes
Accurate gestational age calculation
Precise due date estimation
Crown-rump length (CRL) measurement
Confirm single or multiple pregnancy
Early fetal development assessment
Immediate verbal results and report
When Should I Book?
8-10 Weeks
Earliest accurate dating. CRL measurement reliable. Clear fetal pole visible.
11-13 Weeks
Optimal timing. Most accurate dating window. Combined with NT scan if needed.
14+ Weeks
Later dating possible. Less accurate than early scans. Head measurements used.
Recommended: We recommend booking between 10-13 weeks for the most accurate dating. This is the optimal window for crown-rump length measurement, which provides the most reliable due date calculation.
What to Expect
Before Your Scan
- Drink 2-3 glasses of water 1 hour before
- Arrive with a moderately full bladder
- Bring your maternity notes if available
- Allow 20-30 minutes for appointment
During Your Scan
- Lie comfortably on the examination couch
- Warm gel applied to your abdomen
- Precise measurements taken of baby
- Due date calculated and explained
After Your Scan
- Receive your accurate due date
- Printed images of your baby (2-4 photos)
- Detailed scan report for your records
- Advice on next recommended scans
Why Choose London Ultrasound?
Expert Sonographers
All scans performed by HCPC-registered sonographers with specialist training in early pregnancy assessment and dating accuracy.
Same-Day Appointments
Flexible appointment times including evenings and weekends. No long NHS waiting lists—book your scan when you need reassurance.
Accurate Results
State-of-the-art ultrasound equipment ensuring precise measurements and reliable due date calculations for optimal antenatal care planning.
Common Questions
Why is dating important?
Accurate dating ensures proper timing of antenatal screening tests, helps monitor fetal growth appropriately, and allows planning for delivery. NHS dating scans are offered between 10-14 weeks for this reason.
How accurate is a dating scan?
Dating scans between 8-13 weeks are accurate to within 3-5 days. This is more accurate than calculating dates from your last menstrual period, especially if you have irregular cycles or are unsure of your dates.
Can I find out the gender at a dating scan?
Gender determination is not possible at dating scan stage (before 14 weeks). The external genitalia are not sufficiently developed. Gender scans are typically performed from 16 weeks onwards.
What if my dates don't match my calculations?
It's common for scan dates to differ from period-based calculations. The scan measurement is more accurate and will become your official due date. Your midwife will update your maternity notes accordingly.