How is a dating scan performed? A dating scan is carried out by ultrasound. A sonographer, who is usually a radiographer or a midwife trained in ultrasound, will complete your scan. If the scan is after 10 weeks, ultrasound recordings are usually made through your abdomen.

How is dating ultrasound done?

The ultrasound technician will put some warm gel on your tummy and move a small hand-held device (transducer) over your skin to get views of your baby (NHS 2015b, SOGC 21019). It wont hurt, although you may feel a little pressure on your tummy and from your full bladder.

Can a dating ultrasound be 2 weeks off?

As pregnancy progresses, the accuracy of an ultrasound for predicting due dates decreases. Between 18 and 28 weeks of gestation, the margin of error increases to plus or minus two weeks. After 28 weeks, the ultrasound may be off by three weeks or more in predicting a due date.

Is baby fully developed at 31 weeks?

Babies born at 31 weeks are considered to be very preterm. Because they are not fully developed yet, their features may look different. Their skin may appear translucent. Their head may be disproportionately larger than the rest of their body.