The most commonly used formula for estimating gestational age has been Hadlock's formula which uses biparietal diameter, head circumference, femur length and abdominal circumference.

Hadlock’s formula (1985) combining abdominal circumference, femur length and biparietal diameter ranked highest. As sonographic estimation of fetal weight (EFW) carries substantial impact ...

The prenatal EFW was assessed using a Hadlock formula incorporating the biparietal diameter (BPD), head circumference (HC), AC and femur length (FL) (Log10 (weight)=1.3596−0.00386 × AC × FL+0. ...

ATLANTA (Feb. 1, 2016)--In a study to be presented on Feb. 6 at 8:45 a.m. EST, at the Society for Maternal-Fetal Medicine's annual meeting, The Pregnancy Meeting™, in Atlanta, researchers will ...