Dating ultrasound heartbeat
The scan will usually show that your pregnancy is less far along than suggested by your LMP. This means that accurate dating reduces your chance of having your labour induced because your baby is thought to be overdue. As long as the timings are right, you can have the NT scan and blood test at the same appointment as your dating scan. That's because the screening test needs an accurate due date to be reliable. Hormones in your blood vary according to your stage of pregnancy.
You may know when your LMP was, but not when you actually conceived.
That will happen at your next routine scan at about 20 weeks However, some major problems can be seen at your dating scan, such as issues with the umbilical cord or with your baby's skull or abdominal wall.