Comparison of the efficacy between ultrasound measurement of cross-sectional area of the umbilical cord and Hadlock's formula in the prediction of neonatal birth weight at term gestation: cross-sectional study

Document Type : Original Article

Authors

1 Department of Obstetrics and Gynecology, Faculty of Medicine, Ain Shams University, Cairo, Egypt

2 Department of Obstetrics & Gynecology, Faculty of Medicine, Ain Shams University

Abstract

The accurate calculation of birth weight at term gestation is critical in labor and delivery management. Hadlock's formula is the most commonly used ultrasonic approach, but it is still prone to error.   
Aim: To evaluate the efficacy and accuracy of ultrasound assessment of umbilical cord cross-sectional area to Hadlock's formula in predicting birth weight at term gestation. 
Patients and Methods: This cross-sectional study comprised 220 pregnant women with an uncomplicated, singleton pregnancy and a gestational age of 37 to 41 weeks + 6 days who were admitted with early labor or were scheduled for elective cesarean section. All women had EFW using Hadlock's formula (HC, BPD, AC, and FL), as well as measurement of the cross-sectional area of the umbilical cord, umbilical arteries, and umbilical vein within one cm of the umbilical cord's insertion into the fetal abdomen, and the results were compared to neonatal birth weight. 
Results: There was a significant positive correlation between measurement of EFW using Hadlock’s formula and umbilical cord and its components when compared to birth weight (P= 0.001). The correlation strength of the umbilical cord with the birth weight was higher than that by Hadlock’s formula with the value of coefficient of determinant R2= 0.493 for umbilical cord area versus R2= 0.274 for Hadlock’s. 
Conclusion: The cross-sectional area of the umbilical chord predicted birth weight more accurately. This study's normalcy metrics can be used as a reference for future studies that may associate such characteristics with embryonic growth problems.

Keywords