Early dating ultrasound
The sonographer estimates when your baby is due (the estimated date of delivery, or EDD) based on the baby's measurements.
The dating scan can include a nuchal translucency (NT) scan, which is part of the combined screening test for Down's syndrome, if you choose to have this screening.
If you're offered further tests, you will be given more information about them so you can decide whether or not you want to have them.
You'll be able to discuss this with your midwife or consultant.
Ultrasound scans can sometimes find problems with the baby.
The first scan is sometimes called the dating scan.
This is because most babies are healthy and do not have abnormalities. If a problem is found or suspected, the sonographer may ask for a second opinion from another member of staff.
You might be offered another test to find out for certain if there is a problem.
Most scans are carried out by specially trained staff called sonographers.
The scan is carried out in a dimly lit room so the sonographer is able to get good images of your baby. You'll then be asked to lower your skirt or trousers to your hips and raise your top to your chest.