the relationship of three variables gestational age , fetal weight , and fetal crown-rump length can also be expressed mathematically : gestational age in days = 15.335 + 3.9805 ( crown-rump length in cm ) -0.0675 ( weight in grams ) equations for crown-rump length or weight were calculated , but the inaccuracy of these expressions is too great to allow practical use .
C0751992
fetal
C0005910
weight