The Relativity For Predicting Fetal Weight By Ultrasound And Clinical Measurement

Objective To investigate the birth weight predicting by ultrasound and clinical measurement in Xinjiang. To build the regression equation of estimated fetal weight(EFW).Methods We elected three hundred pregnant one week before delivery from January in 2009 to January in 2010. To measure the parturient the biparietal diameter (BPD), femur length (FL), fetal abdominal circumference (FAC), transverse cerebellar diameter(TCD) by ultrasonic and the fundus height of the uterus(GUH),abdominal circumference (GAC),the years old of pregnant,pregnatal weight,increased weight,contraction and relaxation peak value ratio(S/D).Finally,we built the regression equation and analized the factors related to birth weights.The calculated value of fetal body weight, as well as the estimated parameters of the fetal body was compared with the actually measured values immediately after birth.Results There were correlated with neonatal birth weight on FAC (r=0.696),pregnatal weight (r=0.292) GAC(r=0.303),BPD(r=0.552),GUH(r=0.439),FL(r=0.429),TCD (r=0.348),S/D(r=0.144), There was significant correlation between FAC and birth weight.The standardised coefficient is 0.436.But there was no significant difference in abdominal circumference and TCD,pregnatal weight,S/D.We got the regression equation of predicting birth weight:EFW(Kg)= 3.944+0.006FAC+0.034BPD+0.036×GUH+0.013FL(F=46.294, P=0.000, R2=0.611). Among the 300 cases,202 had absolute error less than 200g,with an agreement rate of 67.4%.237 cases had relative error less than 10%, with an agree mentrate of 79.0%.Conclusions The best predictor of birth weight was Ultrasound measurement of FAC in the single method; Prenatal ultrasound with FAC and BPD indexes can predict fetal weight more accurate compared to the single method; The best method was the ultrasound combination with clinical measurement.