Tracking Fetal Growth: A Comprehensive Guide to Estimating Age with BPD Measurements from 12 Weeks to Full Term.

The  biparietal diameter (BPD) is a measurement commonly used during ultrasound examinations to estimate the age of the fetus. The BPD is the distance between the two parietal bones of the fetal skull and is typically measured in millimeters. Here is a general guide to the size of BPD and age estimation in USG from 12th week to the end of the pregnancy:

• 12 weeks: The average BPD is around 16mm, and the estimated age of the fetus is around 12 weeks.

• 13 weeks: The average BPD is around 21mm, and the estimated age of the fetus is around 13 weeks.

• 14 weeks: The average BPD is around 27mm, and the estimated age of the fetus is around 14 weeks.

• 15 weeks: The average BPD is around 33mm, and the estimated age of the fetus is around 15 weeks.

• 16 weeks: The average BPD is around 39mm, and the estimated age of the fetus is around 16 weeks.

• 20 weeks: The average BPD is around 58mm, and the estimated age of the fetus is around 20 weeks.

• 24 weeks: The average BPD is around 68mm, and the estimated age of the fetus is around 24 weeks.

• 28 weeks: The average BPD is around 79mm, and the estimated age of the fetus is around 28 weeks.

• 32 weeks: The average BPD is around 89mm, and the estimated age of the fetus is around 32 weeks.

• 36 weeks: The average BPD is around 97mm, and the estimated age of the fetus is around 36 weeks.

It is important to note that these measurements and estimated ages are general guidelines and can vary from one pregnancy to another. Additionally, ultrasound measurements are just one tool used to estimate fetal age, and other factors such as maternal history and physical exam findings may also be taken into account.

Prof Fazal Ahmad 

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