Accuracy of Various Ultrasonographic Formulas in Predicting Estimated Fetal Weight (EFW): A One-Year Cross-Sectional Study

Abstract

Accurate estimation of fetal weight is crucial for managing pregnancies and planning delivery. A one-year cross-sectional study was conducted at a tertiary referral hospital, involving 200 pregnant women with singleton pregnancies who underwent routine obstetric ultrasound scans in their third trimester. This study aimed to evaluate the accuracy of various ultrasonographic formulas in predicting estimated fetal weight (EFW) in a clinical setting.  The study compared the accuracy of three commonly used ultrasonographic formulas for predicting EFW: Hadlock’s formula, Shepard’s formula, and the Johnson formula. The actual birth weight (BW) of the newborns was used as the reference standard for evaluating the prediction accuracy of the formulas. The results showed that Hadlock’s formula provided the closest estimates of EFW, with a mean absolute error of 5.2%, followed by Shepard’s (7.4%) and Johnson’s formula (8.6%). Additionally, the sensitivity and specificity of Hadlock’s formula for identifying fetal growth restriction (FGR) were higher than the other formulas. This study concluded that ultrasonographic formulas, particularly Hadlock’s formula, are reliable for predicting EFW and assessing fetal growth. However, the study recommends that ultrasound should be combined with clinical assessment for optimal management of pregnancies with suspected fetal growth abnormalities.

Keywords: Ultrasonography, Estimated Fetal Weight (EFW), fetal growth, cross-sectional study, accuracy, prenatal care, formulas, ultrasound prediction.