ULTRASONOGRAPHIC MEASUREMENTS OF FETAL FEMUR LENGTH IN NORMAL PREGNANT WOMEN : A CASE SERIES STUDY

Dr. Pranita R. Viveki; Dr.V.S. Shirol

Volume : VII, Issue : IV, April - 2018

ULTRASONOGRAPHIC MEASUREMENTS OF FETAL FEMUR LENGTH IN NORMAL PREGNANT WOMEN : A CASE SERIES STUDY

Dr. Pranita R. Viveki, Dr. V. S. Shirol

Abstract :

Background:The femur is generally preferred over the other long bones as a means of predicting gestational age (GA)because of its size, visibility and ease of measurement. Objectives: 1. To establish a reference table for femur length (FL) in normal pregnant women of 20 to 38 weeks of gestation from Belagavi District, Karnataka.2. To find out the predictive accuracy of gestational age determined by FL with gestational age determined by LMP method.Materials and Methods: The data was collected by using predesigned pretested questionnaire from September 2016 to January 2018. Total 768 singleton pregnant women with minimum 30 cases for each gestational week from 20 to 38 weeks of gestation, fulfilling inclusion and exclusion criteria were studied. Statistical Analysis: The data was analyzed using Statistical Package for Social Sciences (SPSS) version 20. For each gestational week percentages, mean, standard deviation, range, standard error, percentiles and regression equation etc. were performed for femur length. Results: The regression equation derived for FL measurements was GA = 5.358 + (4.40 X FL in cm) where correlation coefficient �r� = 0.977 (highly correlated) and proportion of variation in dependent variable (GA) – R²= 0.955. By this regression equation, the accuracy in prediction of gestational age by FL measurement alone was ranging from 96.12 % at 38 weeks to 99.96 % at 23 weeks of gestation. Conclusion: The present study findings confirmed that the fetal FL measurements significantly vary among different population groups due to genetic, racial, and ethnic factors. So generation of population specific reference tables and regression equations for various fetal biometric parameters by a large scale study at national level is required for more precise reporting of GA and expected date of delivery (EDD) by ultrasonography.