The most accurate time is between 8 and 11 weeks gestation. Learn more about how and when it is performed. There are two ways of having a seven week ultrasound. When an ultrasound is done between weeks of pregnancy, gestational weeks are considered as being within 10 days of accuracy. Back to Your pregnancy and baby guide.
If you have more than one ultrasound during your pregnancy, giving you 'multiple dates', then the earliest ultrasound estimate should be used, because it will be more accurate.
Ask a midwife: When should I get a dating scan?
I agree to receive communication about exclusive promotions, offers and products from Huggies and other Kimberly-Clark brands. The person performing the scan is called a sonographer. The average weight is less than 1 gram. Foods to avoid during pregnancy and why. An epic birth story. When should I get a dating scan? Tell us a little bit about your child.