Ultrasound Fetal Weight Estimation: How Accurate Are We Now Under Emergency Conditions?

Ultrasound Med Biol. 2015 Oct;41(10):2562-6. doi: 10.1016/j.ultrasmedbio.2015.05.020. Epub 2015 Jul 9.

Abstract

The primary aim of this study was to evaluate the accuracy of sonographic estimation of fetal weight when performed at due date by first-line sonographers. This was a prospective study including 500 singleton pregnancies. Ultrasound examinations were performed by residents on delivery day. Estimated fetal weights (EFWs) were calculated and compared with the corresponding birth weights. The median absolute difference between EFW and birth weight was 200 g (100-330). This difference was within ±10% in 75.2% of the cases. The median absolute percentage error was 5.53% (2.70%-10.03%). Linear regression analysis revealed a good correlation between EFW and birth weight (r = 0.79, p < 0.0001). According to Bland-Altman analysis, bias was -85.06 g (95% limits of agreement: -663.33 to 494.21). In conclusion, EFWs calculated by residents were as accurate as those calculated by experienced sonographers. Nevertheless, predictive performance remains limited, with a low sensitivity in the diagnosis of macrosomia.

Keywords: Birth weight; Fetal weight; Neonatal; Ultrasound estimation.

MeSH terms

  • Clinical Competence / statistics & numerical data*
  • Emergency Medical Services / statistics & numerical data*
  • Female
  • Fetal Weight*
  • Humans
  • Image Interpretation, Computer-Assisted / methods*
  • Male
  • Observer Variation
  • Pregnancy
  • Reproducibility of Results
  • Sensitivity and Specificity
  • Tunisia / epidemiology
  • Ultrasonography, Prenatal / methods*
  • Ultrasonography, Prenatal / statistics & numerical data*