To Verify The Accuracy Of Youssef Formula In Estimating Fetal Biacromial Diameter And Explore Its Clinical Application Value

Objective: To explore the relationship between fetal biological diameter measured by ultrasound and fetal biacromial diameter.To verify the correctness of Youssef formula for estimating fetal biacromial diameter,so as to provide a possibility for the prediction of shoulder dystodia.To determine whether fetal biacromial diameter is related to neonatal weight and body mass index(BMI).Methods: From September 2018 to April 2019,152 singleton pregnant women with a gestational period of 37-42 weeks from the First Affiliated Hospital of China Medical University were selected for fetal ultrasound measurement within 3 days before delivery,including: biparietal distance,head circumference,chest circumference,abdominal circumference,humeral length,femur length,thoracic transverse diameter and midpoint diameter of upper arm.Shoulder diameter,weight and body length of newborns were measured within 1 day after delivery.1.The correlation between biparietal distance,head circumference,chest circumference,abdominal circumference,humeral length,femur length and shoulder diameter of newborn were analyzed.2.Judge whether the biacromial diameter estimated by Youssef formula is consistent with that of newborn.3.Determine whether fetal biacromial diameter estimated by Youssef formula was correlated with neonatal weight and BMI.4.Analyze the difference of fetal biacromial diameter estimated by Youssef formula between macrosomia group and non-macrosomia group,if there is a difference,the critical value is determined.Results: There was a positive correlation between fetal biparietal distance,head circumference,chest circumference,abdominal circumference,humeral length and femur length and neonatal shoulder diameter,and the correlation coefficients were 0.519,0.462,0.534,0.477,0.346 and 0.311,respectively(P=0.001).The biacromial diameter of fetus estimated by Youssef formula is consistent with that of newborn(P=0.719).There was a positive correlation between fetal biacromial diameter estimated by Youssef formula and neonatal weight and BMI,and the correlation coefficients were 0.477,0.404(P=0.001).The difference of fetal biacromial diameter estimated by Youssef formula between the macrosomia group and the non-macrosomia group was statistically significant(P=0.019).When estimated fetal shoulder diameter was 13.89 cm,the sensitivity and specificity of predicting macrosomia were respectively 91.7% and 52.1%(P=0.005).Conclusions: 1.It is verified that the biacromial diameter of fetus estimated by Youssef formula is consistent with that of newborn.2.There is a positive correlation between fetal biacromial diameter and neonatal weight,BMI(weight / height 2),which can be used to predict fetal weight and BMI.The sensitivity of estimated fetal biacromial diameter? 13.89 cm by Youssef formula to predict macrosomia is high,but the specificity is low,it has certain clinical application value.