Increased accuracy of fetal weight estimation with a gender-specific weight formula

Fetal Diagn Ther. 2008;24(4):321-6. doi: 10.1159/000159777. Epub 2008 Oct 6.

Abstract

Objective: To test whether Schild's sex-specific formula for estimating fetal weight is more accurate than commonly used regression formulae.

Methods: The gender-specific formula and 10 widely used equations were evaluated in a group of 989 pregnancies. Each fetus underwent ultrasound examination with complete biometric parameters within 7 days before delivery.

Results: Over the whole weight range and in the subgroup of newborns with a birth weight between 2,500 and 3,999 g, the sex-specific weight formula from Schild demonstrated the best level of accuracy. For infants with a birth weight of less than 2,500 g as well as for macrosomic newborns, the gender-specific formula did not improve fetal weight estimation.

Conclusion: In pregnancies where fetal gender is known, Schild's regression formula should be used when fetal weight lies within the range of 2,500-3,999 g.

Publication types

  • Clinical Trial
  • Comparative Study
  • Validation Study

MeSH terms

  • Adolescent
  • Adult
  • Biometry / methods*
  • Birth Weight
  • Female
  • Fetal Weight*
  • Gestational Age
  • Humans
  • Male
  • Middle Aged
  • Models, Biological*
  • Pregnancy
  • Prospective Studies
  • Regression Analysis
  • Reproducibility of Results
  • Sex Factors
  • Ultrasonography, Prenatal / methods*
  • Ultrasonography, Prenatal / standards*
  • Young Adult