How fetal weight is estimated

Since they can't use a scale I wondered how doctors could estimate the fetal weight.

Here's the answer which explains why it's not always accurate:

To estimate your baby's fetal weight, a registered diagnostic medical sonographer or physician will do an ultrasound. We measure the baby:


•Around the head (head circumference)
•Across the head (biparietal diameter)
•Around the abdomen (abdominal circumference)
•Length of the thigh bone (femur)
These measurements are entered into the computer in the Perinatal Assessment Center. It computes the approximate weight for the baby at this gestational age. It also gives us some idea of how your baby's size compares to other babies at that gestational age. The percentile tells us where in 100 babies, with 1 being the smallest and 100 being the biggest, your baby's estimated weight falls. If you baby is less than the 10 percentile, other tests may be indicated.

Re: How fetal weight is estimated

I'm sure its not always inaccurate, but it seems to me that every baby ends up being less than the estimated weight.

Re: How fetal weight is estimated