Comparative Study Between Clinical and Ultrasonography Estimation of Fetal Weight and Its Correlation with Actual Birth Weight

Deena Mohan E.

Abstract: Objective: Fetal weight estimation is critical for managing labour, delivery, and perinatal care. This study aimed to compare the accuracy of clinical estimation using standard palpation methods and Dare?s formula with ultrasonographic estimation employing biometric parameters (e. g. biparietal diameter, abdominal circumference, and femur length using Hadlock?s formula) in predicting actual birth weight. Methods: In a prospective observational study, 200 term pregnancies with singleton gestations were enrolled. Clinical fetal weight estimation was performed by trained clinicians using symphysio - fundal height and abdominal girth measurements, which were applied to Dare?s formula. Ultrasonographic estimation was conducted by a sonographer blinded to the clinical result using standard biometric measurements and Hadlock?s regression formula. The estimated fetal weights (EFWs) from both methods were then compared with the actual birth weight measured within 30 minutes of delivery. Accuracy was assessed by computing mean percentage error (MPE), mean absolute percentage error (MAPE), and the proportion of estimates within ?10% of actual birth weight. Results: Both estimation methods demonstrated significant correlation with actual birth weight (clinical: r = 0.71; ultrasound: r = 0.74; P < 0.001 for both). On average, the ultrasonographic method showed a lower MAPE (approximately 7%) compared to the clinical method (approximately 12%). Subgroup analyses revealed that while clinical estimation had comparable performance in mid - range fetal weights, ultrasonography outperformed in cases of suspected macrosomia and in scenarios complicated by maternal obesity. Conclusion: Ultrasound estimation of fetal weight was found to be more precise overall than clinical estimation. However, in settings where ultrasound is unavailable, clinical estimation remains a useful, cost?effective alternative. Integration of both methods?along with maternal perception in experienced multiparous women may optimize fetal weight prediction and support obstetric decision - making.

Keywords: Fetal weight estimation, Clinical assessment, Ultrasonography, Dare?s formula, Hadlock?s formula, Birth weight correlation