The standardized comparison of femur length with age, i.e. the femur length standardized value comparison table, is mainly used to judge the growth and development of the fetus.
Since 1 to 12 weeks of pregnancy is the process from the fertilization of the egg to the initial growth and development of fetal body organs, the femur length measured at this time is mostly inaccurate, so it is necessary to measure and calculate the femur length from the 13th week of pregnancy.
According to the standardized comparison table of femur length and age, the average values of femur length in each period are as follows: 1.17±0.31cm in the 13th week of pregnancy; 1.38±0.48cm in the 14th week of pregnancy; 1.74±0.58cm in the 15th week of pregnancy; 2.10±0.51cm in the 16th week of pregnancy; and 2.71±0.46cm in the 18th week of pregnancy;
3.35±0.47cm in 20th week of pregnancy; 3.82±0.47cm in 22nd week of pregnancy; 4.36±0.51cm in 24th week of pregnancy; 4.81±0.41cm in 26th week of pregnancy; 5.35±0.55cm in 28th week of pregnancy; 5.77±0.47cm in 30th week of pregnancy and so on, please refer to the values provided by the doctor.