Comparison Of Shepard And Hadlock Method Of Sonographic Fetal Weight Estimation In Term Pregnancy

Abstract

Background: Accurate fetal weight estimation is a key component of antenatal care, influencing obstetric management decisions and perinatal outcomes. Ultrasonography-based formulas, including the Shepard  and Hadlock methods, are widely used; however, variations in their accuracy may impact clinical judgment.

Objective: To compare the accuracy and precision of the Shepard  and Hadlock methods in estimating fetal weight in term pregnancies.

Methodology: This cross-sectional comparative study was conducted on 50 term pregnant women. Estimated fetal weight (EFW) was calculated using both the Shepard  and Hadlock ultrasonographic formulas for each participant. Paired sample analysis was performed to compare mean EFWs between the two methods. Measures of variability, including standard deviation and standard error of the mean, were used to assess precision. Additional variables such as maternal sociodemographic characteristics and fetal presentation were evaluated for their potential influence on estimation differences.

Results: The mean EFW calculated by the Shepard  method was 1.9987 kg, while the Hadlock method yielded a slightly higher mean of 2.06162 kg. Although both methods showed comparable results, the Hadlock method demonstrated relatively greater accuracy in fetal weight estimation. The difference between the two methods was not statistically significant.

Conclusion: Both Shepard  and Hadlock methods provide reliable estimates of fetal weight in term pregnancies, with the Hadlock method showing marginally better accuracy. Selection of an appropriate estimation method is important for optimal clinical decision-making. Further large-scale studies are recommended to validate these findings and improve estimation techniques.