ABSTRACT
Background: Prenatal estimation of birth-weight is of utmost importance to predict the mode of delivery. This is also an important parameter of antenatal care. This study was conducted to evaluate the accuracy of estimated fetal weight by ultrasound, compared with actual birth weight.Methods: This was a prospective and comparative study comprising 110 pregnant women at term. Patients who had their sonography done within 7 days from date of delivery were included. Fetal weight was estimated by Hadlock 2 formula, the software of which was preinstalled in ultrasound-machine. The estimated fetal weight was compared to the post-delivery birth-weight. The Pearson's correlation coefficient was used and the accuracy of sonographic fetal weight estimation was evaluated using mean error, mean absolute error, mean percentage error, mean absolute percentage error and proportion of estimates within 10% of actual birth weight.Results: Mean estimated and actual birth weights were 3120.8±349.4 gm and 3088.2±404.5 g respectively. There was strong positive correlation between estimated fetal weight and actual birth weight (r = 0.58, p<0.001). The mean percentage error and mean absolute percentage error of ultrasound fetal weight estimations were 1.96±11.8% and 8.7±8.2% respectively. The percentage of estimates within ±10% of the actual birth weight was found to be 67.3%. In 23% of the cases, ultrasound overestimated the birth weight. In 13% of the cases, ultrasound underestimated the birth weight.Conclusions: There was strong positive correlation between actual and sonographically estimated fetal weight. So, ultrasonography can be considered as useful tool for estimating the fetal weight for improving the perinatal outcome.
ABSTRACT
Background: Accurate estimation of fetal weight is of paramount importance in the management of labour and childbirth. In developing countries including India, estimation of fetal weight by clinical method is important as ultrasound is not available in all health care settings. In view of this, the present study was conducted to estimate the fetal weight assessed by clinical and ultrasound method and correlating with the birth weight.Methods: A cross-sectional study was conducted to estimate fetal weight clinically by using Johnson’s formula and sonographically based on Hadlock’s formula in the Department of Obstetrics and Gynecology in collaboration with Department of Radiodiagnosis, Regional Institute of Medical Sciences, Imphal from October 2016 to March 2018. The study consisted of 525 pregnant women between 37 to 40 weeks of gestation in whom delivery was anticipated within one week of fetal weight estimation by clinical and ultrasound method and correlating it with the baby’s birth weight measured immediately after delivery. Analysis was done using Chi-square and Student’s t-test and p-value of <0.05 was taken as significant.Results: Both methods showed positive correlation with birth weight but clinical method (r=0.925) had stronger correlation compared with ultrasound method (r=0.508).Conclusions: Fetal weight estimation using Johnson’s formula had stronger correlation with the birth weight than ultrasound method and hence, useful for developing countries and all health care workers may be sensitized about the method.