A Comparative Study of Fetal Weight  Estimation Using Ultrasound and Johnson�s  Formula and its Correlation with Actual Birth  Weight

Dr.Kavitha.b; Dr.G.C.Prabhakar; Dr. Shaivalini.k; Dr.Suprada.k

Volume : III, Issue : II, February - 2014

A Comparative Study of Fetal Weight Estimation Using Ultrasound and Johnson�s Formula and its Correlation with Actual Birth Weight

Dr. Kavitha. B, Dr. G. C. Prabhakar, Dr. Shaivalini. K, Dr. Suprada. K

Abstract :

Introduction: During the last two decades, estimated fetal weight has been incorporated into the standard routine antepartum evaluation of high risk pregnancies and deliveries. A fetus or newborn infant whose weight is appreciably above or below normal is at increased risk of physical and intellectual impairment .Objectives: To estimate sensitivity and specificity of birth weight determined by ultrasound and by Johnson�s formula with actual birth weight in birth weight estimation. MATERIALS AND METHODS : A prospective comparative study was conducted on 180 women booked at Mamata General Hospital,khammam between 38-40 weeks of gestation and in early labour in the same gestational period in whom ultrasound was done during last one week before delivery ; the ultrasound and Johnson�s formula were correlated .RESULTS : Comp� both the methods, ultrasound was found to be more accurate in the range of 2500-3500g. The sensitivity and specificity , positive predictive value, negative predictive value of Johnson�s formula in the present study were 86.4%,59.3%,90.7%,48.7% respectively and ultrasound estimation of fetal weight were 93.1%, 71.8%,93.9%,71.8%.in all aspects ultrasound was superior to clinical method of fetal weight estimation. CONCLUSION : Ultrasound estimation of fetal weight is better reliable method than Johnson�s formula wherever facilities are available. It can be used in eech and other malpresentations where Johnson�s formula cannot be applied. It has high sensitivity and specificity to estimate fetal weight and correlates significantly with actual birth weight.