Is manual foot lenght measurement of comparable value to ultrasound femur and humerus measurement in anatomical studies for the assessment of foetal age?

Contemporary anatomical studies require reliable methods for determining foetal age. Menstrual age is often found to be inadequate. A combination of several anatomical features showing age-dependency may result both in exact age approximation and pathology detection. The authors compared the manual foot length measurements with the ultrasound femur and humerus length measurements of aborted foetuses in the calculation of foetal age. The correlation between femur length and foot length as well as humerus length and foot length were statistically significant. The expected value formulae for foot length are presented. The authors conclude that foetal age assessment based on foot length metering is reliable before the 7th calendar month of pregnancy and correlates with ultrasound measurements of the humerus and femur