Introduction: Accurate antenatal estimation of fetal birth weight at term remains fundamental to optimal obstetric management. While ultrasonography represents the reference standard, limited availability in resource-constrained settings necessitates the continued use of simple clinical methods. This study compared the accuracy of clinical formulas and ultrasonography for predicting fetal birth weight at term.
Methods: This prospective, cross-sectional study was conducted over a six-month period at a tertiary care hospital in Chennai. Sixty-three women with singleton, cephalic pregnancies between 37 and 41 weeks of gestation were included. Estimated fetal weight was calculated within 48 hours prior to delivery using Johnson's formula, Dare's formula, and ultrasonography based on the Hadlock formula. Actual birth weight measured immediately after delivery served as the reference standard. Accuracy was assessed using mean percentage error, proportion within ±10% of actual birth weight, Pearson's correlation coefficient, and Bland-Altman analysis.
Results: The mean actual birth weight was 2940 ± 450 g. Ultrasonography demonstrated the highest accuracy (mean percentage error −3.8%, 81% within ±10%, r = 0.89). Johnson's formula showed moderate accuracy (6.4%, 71.4%, r = 0.82), while Dare's formula was less accurate (10.7%, 63.5%, r = 0.78).
Conclusion: Ultrasonography using the Hadlock formula remains the most accurate method for fetal weight estimation at term. Johnson's formula may serve as a reasonable alternative where ultrasound is unavailable...
Keywords: Fetal Weight Estimation; Birth Weight; Ultrasonography, Prenatal; Symphysis-Fundal Height; Fetal Growth.
How to cite this article: Sparsha J, Revathy TG, Kaavya M, Sindhu, A comparative study of clinical methods and ultrasound for prediction of fetal birth weight at term gestation. Int J Drug Deliv Technol. 2026;16(5s): 259-264; DOI: 10.25258/ijddt.16.5s.32
Source of support: Nil
Conflict of interest: None