Dating ultrasound. A dating ultrasound or dating scan is a scan done early in pregnancy (before 12 weeks). It is usually done to check how many weeks pregnant you are and therefore to calculate the estimated due date, but it can be done for other reasons.

How early can a dating ultrasound be done?

Dating ultrasounds are most accurate when they happen between 7-12 weeks, and are calculated by measuring the fetus crown-rump length. This generally predicts the expected date of birth within 5 days.

What is considered an early ultrasound?

Fetal ultrasound is usually done by an ultrasound technologist or doctor in a doctors office, hospital, or clinic. An early fetal ultrasound is one that is done before 18 to 22 weeks of pregnancy. The test takes 15 to 60 minutes.

What is an early dating scan?

Early pregnancy scan (booking or dating scan) The early pregnancy scan is used to check your babys development. Its sometimes called your dating scan as it helps to show how many weeks pregnant you are. Its also used to pick up any health conditions or chromosomal conditions.

Is it bad to have ultrasound early?

An ultrasound during the first trimester appears to be not only safe but, in many cases, essential to confirming a normal pregnancy. Furthermore, the most accurate screening test available for Down syndrome involves a first trimester ultrasound.