The accuracy of ultrasound in the estimation of the actual birth weight at term pregnancies in a sample from Erbil city

Abstract

Background and objectives: Estimation of fetal weight is an important component of maternity health care, especially in the management and planning of the delivery mode, and this will play a big role in newborn and maternal safety. This study has been carried out for providing more knowledge about the accuracy of fetal weight estimation by ultrasound and its correlation with actual weight after birth.Methods: This study was performed in the Radiology Department of the Maternity Teaching Hospital in Erbil city on 407 pregnant women with singleton and in term pregnancies from May 4th, 2015 to April 10th, 2016. The ultrasound examination typically involved estimating fetal weight by using both Hadlock’s and Shepard’s formula, and the actual birth weight of each participant’s neonate was measured immediately after delivery by using a standardized neonatal weighing scale. This study was approved by the Research Ethics Committee of Hawler Medical University.Results: Statistical analysis by t-test indicated that there was a significant difference between the actual birth weight and sonographic estimation of fetal weight using both formulas. The correlation between actual birth weight and sonographic estimation by Hadlock's formula was (R=0.869) while it slightly declined when Shepard’s formula was used (R=0.805). Hadlock's formula showed a better relation with actual fetal weight. This study was showed higher correlation when the time of estimation was within seven days of delivery time, and it was about (R=0.921), and when the time of estimation became more than seven days from delivery, it was showed less correlation (R=0.811).Conclusion: Hadlock’s formula for estimation of fetal weight by ultrasound showed more accurate results, particularly within a time less than seven days from delivery date.