He is better able to identify problems with your baby's development with this information.
Using the date of the last period gives a general idea of that information, but abnormalities in the cycle or inaccuracies in the date affect the calculations.
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.
Much of the baby's development occurs in the first trimester at certain points, making it easier to pinpoint the age based on how much the baby has developed.Data on measurements for different gestational ages allows the machine to calculate an age for your baby by comparing the data.The level of the amniotic fluid also is measured and used in the calculations.It may also help you to avoid feeling disappointed towards the end of your pregnancy if you think your baby is late when he's not. The scan can check that your baby's heart is beating nicely and that he's developing normally.