Study On The Evaluation Of Neonatal Birth Weight Based On Fetal Abdominal Circumference

Objective:This study proposes a fetal weight assessment formula as:EFW=220×FAC-4100.Through the analysis and comparison of 742 cases of original clinical data,the test demonstrates the feasibility of this formula in estimating fetal weight estimation.Methods:For this study,742 fetuses born in the Obstetrics and Gynaecology in Liaocheng Maternal and Child Health Hospital from February 2016 to December 2016 have been chosen,including 716 singletons and 13 twins(26 fetuses).The sex of the newborn is 384 males and 358 females.Four physical parameters of the newborn fetus were detailed measured,separately,which including the biparietal diameter,head circumference,abdominal circumference and femur length.Using the formula proposed in this work and other three formulas,the estimated fetal weights of the newborn babies after delivery were calculated,and then compared with their actual weight.The comparative study were carried out to evaluate the feasibilities of the four formulas in estimating fetal weight.The four formulas are listed as,Formula A1:EFW=220×FAC-4100;Formula A2:EFW=188.4x FAC-3038.7 FormulaA3:EFW=10^(1.3596+0.00064×HC+0.00061×BPD×FAC+0.0424xFAC+0.174xFL-0.00386xFACxFL)Formula A4:EFW=1.07×BPD3+0.3×FAC2×FL Wherein FAC means:fetal abdominal circumference;HC means:head circumference;BPD means:biaparietal diameter;FL means:femur length.Results:1、In view of the fact that Formula A1 proposed in this study is a one-parameter formula of fetal abdominal circumference,and the slope and intercept are integers in the formula,it has good operability for obstetrics and the maternal to fetus without professional knowledge.Assessment of development has important guiding significance.2、According to the estimation of the weight of the fetal sex group,it is found that the difference between the average weight estimated from the four formulas and the true weight is negative in the male infant group,although the formula A3 is negative in the female infant group.The remaining formulas are all positive values,but the average weight estimates calculated by the same formula are smaller in the male infant group than the female infant group,which indicates that gender is an important factor affecting the estimated fetal weight.3、In the estimation of the weight for fetal macrosomia group,the difference between the mean values of calculated weights by the four formulas and the mean values of real weight is negative,that is to say,the four formulas will underestimate the weight of the fetus.The percent of the population whose relative deviation of the calculated weights from the real values less than 15%are through the four formulas 96.4%,94.0%,89.3%,and 90.6%in the order of formulasAl-A4,respectively.The accuracy of formula A1 for weight estimation is significantly higher than that of Formula A2 andFormula A3.The accuracy of Formula A1 and Formula A2 is higher than Formula 3 and Formula 4,which reflects that the single parameter formula predicts the high accuracy of the giant child.The reason may be that for the giant child,the dominant factor determining the weight is the fetal abdominal circumference.4、For the low-weight newborns group,the prediction of the fetal weight by Formula 3 is relatively accurate,in contrast,Formula 1 has the largest deviation.All of the four formulas overestimate the weight,in this case,the multi-parameter formula is better than the single-parameter formula.However,it is important to point out that overestimation of low-weight fetuses can cause clinicians to underestimate the risks that newborns may encounter when coming down to the world.Conclusion:By comparison,the proposed formulas in this word can be applied clinically as the other three ones.Among them,Formula 1:EFW=220XFAC-4100,has only one variable,and the slope and intercept are all integers.Therefore,the estimation of weight through Formula 1 is most easily and convenient,which has evidently higher operability and more convenience for clinicians.Assessment of fetal weight.This formula is suitable for almost all pregnant women.Another important advantage of Formula 1 is that the coincidence rate for the estimation of giant body weight is significantly higher than the other three formulas,so Formula 1 has its unique significance in estimating giant infants.