How accurate is the ultrasound examination? The earlier the ultrasound is done, the more accurate it is at estimating the babys due date. Ultrasounds performed during the first 12 weeks of pregnancy are generally within 3 - 5 days of accuracy. The most accurate time is between 8 and 11 weeks gestation.

Can an ultrasound tell how old a pregnancy is?

An ultrasound is a highly accurate means of dating a pregnancy. In a normal pregnancy, ultrasound can provide an estimate of the gestational age to within five to seven days of accuracy.

Can fetal age be wrong?

After the infant is born, there are a variety of characteristics that can be used to estimate the gestational age. It is possible for gestational age to be inaccurate by up to 2 weeks, even with an accurate LMP date confirmed by other tests.

Is due date by ultrasound accurate?

An ultrasound is actually the most accurate way to date a pregnancy because all fetuses grow at a consistent rate during the first trimester and early second. In other words, if your baby measures 9 weeks 2 days when you have your ultrasound, thats how far along you are, no matter when your last period was.