Comparative Study of Various Methods of Fetal Weight Estimation at Term Pregnancy

OBJECTIVE To make a comparative evaluation of estimation of fetal weight in term pregnancy by u sin g a) abdominal girth (AG) X symphysiof.indal height (SFH) b) Hadlock's formula using ultrasonography c) Johnson's formula and d) Dawn's formula. METHODS The fetal weight in-utero was calculated by usin g the above methods in 200 pregnant women at term. The results were correlated with the actual birth weight. Comp arative analysis of the accuracy of the various methods was done. RESULTS Average error in fetal weight estimation was least with AG X SFH method. Maximum error in fetal weight calculation was mo st marked w ith Dawn's formula and least w ith AG XSFH. 85.5% of cases came within 15% of birth weight by both AG X SFH method and Hadlock's formula using ultrasonography. Standard de viation of predicti on error was lea st w ith Hadlock's ultrasound method, closely followed by AG X SFH method. CONCLUSION Though ultrasound predicts the fetal weight more accurately, AG X SFH which is also equally good should be used in d ay to day practice, especially in places where ultrasound is not available.