Dating Criteria After 14 Weeks

If the date differs based on crown rump length by more than 7 days when it is 9 weeks and 0 to 13 and 6, then consideration should be done to changing the gestational age. So from 14 weeks upwards, now it's time to use second trimester biometric parameters for dating. Looking at 14 weeks, a variety of ultrasound parameters like the bipramidal diameter, the BPD, or the abdominal circumference, the AC or the femoral length can be used to estimate gestantic age.