Estimation of fetal actual weight with various methods in term pregnancy - a comparison.

Objective: To make a comparative evaluation of estimation of fetal weight in term pregnancy by using a) abdominal girth (AG) X symphysiofundal height (SFH) b) Hadlock\'s formula using ultrasonography c) Johnson\'s formula . Methods: The fetal weight in-utero was calculated by using the above methods in 100 pregnant women at term. The results were correlated with the actual birth weight. Comparative 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 most marked with other formulas like Johnsons formula. 85.5% of cases came within 15% of birth weight by both AG X SFH method and Hadlock\'s formula using ultrasonography. Standard deviation of prediction error was least with 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 day to day practice, especially in places where ultrasound is not available.