A Dating Scan can be done from 6 weeks gestation. This is 6 weeks from the first day of your last period (LMP). The purpose of this scan is to accurately date
Ultrasound: Sonogram - American Pregnancy Association
The optimal gestational age for measurement of NT is 11-13 + 6 weeks. . First trimester ultrasound has many advantages, including accurate dating, detection
First trimester ultrasounds - BabyCenter Canada
North Bristol NHS Trust offers a pregnancy-dating scan to all women at 10 – 13+6 weeks of pregnancy. This information There is no evidence that ultrasound scans cause harm to most accurate way of calculating (working out) date of birth.