Does ultrasound dating add two weeks to the due date?

Answer by  Ali41 (1593)

It's based on the approximate date of your last period (i. e. 2 weeks before ovulation). The U/S figures that out by looking at the approximate size of the fetus.

Answer by  Rose (6804)

No, ultrasound dating will give you one of the most accurate pregnancy due date. Doctors will date a pregnancy back to the first day of your last menstrual period. So when you are two weeks pregnant you have yet to even become pregnant. This is why many get confused regarding their due dates.

Answer by  dubhreubel (501)

Ultrasound dating gives you the same dating as you would have if your period was regular on a 28 day cycle. So at 4 weeks pregnant, the baby was conceived two weeks earlier. This is the same if your estimated due date was calculated by using your last menstrual period on an average 28 day cycle or using an ultrasound.