Accuracy of ultrasound in fetal birth weight estimation in term pregnancies. Experience at tertiary care hospital of Quetta, Pakistan

Abstract

Introduction: Ultrasound assessment of prenatal estimated fetal weight (EFW) determination in term pregnancies provides valuable information in the evaluation of fetal growth and planning mode of delivery. Objective: The aim of this study was to assess the accuracy of ultrasound in estimation of fetal birth weight in term pregnancies at Bolan Medical Complex Hospital. Methods: A prospective, Hospital based, cross sectional study was conducted from January 2019 to June 2019. Obstetric ultrasound was done on 470 term pregnancies to determine fetal weight that fulfill the inclusion criteria. Data was collected using questionnaire. The weights of the neonates were confirmed at the expected time of delivery from registration books. Summary statistics computed. Results: Out of 470 pregnant mothers for fetal weight estimation, the accuracy of ultrasound fetal weight estimation within 10% of actual birth weight was 85.5%. The mean absolute error of estimated fetal weight was 226.67gm. The accuracy of weight estimation was seen to decline as the gestational age increased from 87.8% at 37 - 38 weeks, 82.6% at 39-40 weeks and 50% at 41-42 weeks. Overall ultrasound overestimated the fetal weight in those 4000gm. Conclusion: The accuracy of ultrasound in estimation of fetal weight performed in term pregnancies was found to be higher in our study than that reported in other studies. More accurate results are shown in normal birth weight of fetuses and gestational age of earlier weeks of term pregnancies.