Finding out about having twins early in pregnancy also gives you more time to prepare for the birth and for your doctor and midwife to plan your care. Nearly all scans after 10 weeks can be done through your tummy, and most units ask you to arrive with a full bladder.
The sonographer will put some gel on your tummy and move a small hand-held device (transducer) over your skin to get views of your baby.
It may lead to you being given a high chance for Down's syndrome, when your baby is actually developing normally (false-positive result). Addition of non-invasive test to improve screening for pregnant women.
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.
You may need a second scan to check the first scan's findings.
The point of the scan is to work out how many weeks pregnant you are. Ectopic pregnancy and miscarriage: diagnosis and initial management CG 154.
You may have calculated the length of your pregnancy from the first day of your last menstrual period (LMP). 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.