How to calculate gestational age using biparietal diameter

Patient's question:

No

Doctor's answer:

The formula for calculating fetal weight based on biparietal diameter is: fetal weight = biparietal diameter (cm) multiplied by 900 minus 5200. Due to individual differences among expectant mothers, there will inevitably be some error in the fetal weight calculated from ultrasound data. Expectant mothers can only use it as a reference.