Ultrasounds and dating conception
The measurements also are more accurate in the beginning, when babies' growth rates usually are similar. If your baby is larger, his measurements won't line up with others at the same gestational age.
The dating scan isn't designed to look for more subtle abnormalities, though. Ultrasounds commonly are used to determine the age of a fetus.The ultrasound machine and software allows the technician to see the baby's development and measure the baby.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.