Estimation of Gestational Age by Occipito Frontal Diameter using UltraSound

Abstract

On ultrasound examination found common parameters for assessing gestational age and known normal growth of fetus, these parameters e. g femur length (FL) ,biparital diameter (BPD), head circumference (HC),abdominal circumference(AC). Measuring occipito frontal diameter (OFD) along with these parameters could be of great values for estimation of gestational age. The main objective of this study was to estimate the gestational age by using occiptofrontal diameter and it compare with other common parameters (FL&BPD) which compare the age in weeks and it measured the length in centimeter. Fifty pregnant Sudanese women were included in this study all women their age between 17-42 years in the second and third trimester came to ultrasound department, checking for antenatal routine ultra sound examination at Haj Alsafi educational hospital, who had normal and singleton pregnancy. After measuring the FL and BPD, measured the OFD from outer to outer, then calculated the GA by OFD and correlating with GA by FL and BPD. The study found correlation between GA from OFD and GA from FL as r = 0.958, correlation between GA from OFD and which that from BPD as r = 0.967, and also correlation between GA from OFD and expected gestational age in which r = 0.952 that means the study found the strong relation between them .The study also showed linear regression between OFD was measured in centimeters and expected gestational age in weeks. Thus OFD is significant in estimating gestational age, from 13 weeks till “25-30” weeks of gestational age.