FETAL MASS DETERMINATION

 

Fetal growth failure = fetal mass (weight) that is below the lower limit of normal (for the particular population being studied).

The only diagnostic factors that truly reflect fetal mass are:

 

FORMULAS FOR DETERMINING FETAL WEIGHT

 

Formulas For Determining Fetal Weight

 

ERRORS IN ESTIMATING FETAL WEIGHT


 
 

Variable

Estimated Error
± 2 SD

AC
HC/AC
AC/FL
HC/AC/FL

FL/AC/BPD (2)

BPD/AC (2)
Composite fetal volume
Neonatal measurement (direct)
Variation by neonatal density

27%
18-25%
16%
15-17%

9.58%

11.86%
8-10%
8-10%
8-21%

 

 

 

REFERENCES

  1. Manning F. Fetal Medicine: Principles and Practice. Appleton and Lange, Connecticut 1995:346.
  2. Fleming A, Riva JD, McAdoo G. Estimation of fetal weight by ultrasound in term pregnancy. JDMS 1996;12:7-10