Multivariate Analysis Of Fetal Body Weight Ultrasound Estimation

Objective:We assess the accuracy of estimated fetal weight measured by B-US via comparing actual birth weight with estimated fetal weight measured by B-US in three weeks before birth between normal and overweight/obesity pregnant women,to provide basis for clinical decision and reduce maternal and birth injury,to improve the obstetric management objective.Methods:We conducted 480 pregnant women without complication,who delivered in Shandong Maternal and Child Health Hospital from 2015-07-2016-06 to cohort study.The data were measured by Samsung WS80A color doppler ultrasonic diagnostic instrument.The estimated fetal weight was calculated with Hadlock formula.The absolute percentage error was assessed by GAP.The relationship between BMI and B-US performance was assessed by linear regression.Results:1.Different with the normal weight pregnant women,the low accuracy of B-US had statistical significance in overweight/obesity pregnant women(p=.044).In uni-variant analysis,the absolute percentage error and absolute error were positively related to BMI.2.The average difference between the estimated fetal weight measured by B-US and actual birth weight in abnormal glucose tolerance pregnant women was significant higher than that in normal glucose tolerance pregnant women(235.93±189.40 g vs 226.45±185.43 g;p<0.05).3.The average weight difference between the estimated fetal weight measured by B-US and actual birth weight had no statistical difference in polyhydramnios group and oligohydramnios group.However,the average weight difference of abnormal amniotic fluid(polyhydramnios group and oligohydramnios group)pregnant women was significantly higher than that in normal amniotic fluid group.Conclusions:1.The accuracy is related to the gradual increase in the number of ultrasound scanning over time,The accuracy worsened with the number of days between ultrasound scanning and delivery increased,and the difference is greater for BMI greater than 25.2.The abnormal glucose tolerance influence the accuracy of fetal weight estimated by B-US.3.Either polyhydramnios or ologoamnios could reduce the accuracy of fetal weight estimated by B-US.