الفهرس 
Importance of fetal weight estimationOnly 14 pages are availabe for public view
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Abstract
Background: Accurate estimation of fetal weight is considered the corner stone of fetal growth assessment. In every day obstetric practice, EFW is a key tool for identifying and managing both small fetuses (BW ≤ 2500 g) and large fetuses (BW ≥ 4000 g). A fetus with growth restriction is at increased risk of hypoxia and perinatal death, on the other hand a macrosomic fetus is associated with an increased risk of cesarean section, fetal injury and maternal complications. Armed with this information informed decisions about delivery can be taken, thereby minimizing perinatal morbidity and mortality. For the past 2 decades, sonographic estimation of gestational age and fetal weight has relied on a series of formulas derived from biometric measurements of the fetus, including the fetal head, abdomen and femur. These estimates are not highly accurate, with 86.5% of estimates being within 15% of actual birth weight. Formulas incorporating thigh circumference (TC) measurements may be proven most useful in predicting fetal weight when growth abnormalities are present. Fetal growth aberrations are associated with changes in the soft tissue mass which is decreased in IUGR. Pediatric experience has shown that TC is one of the parameters that reflect soft tissue mass.
Objective: The aim of this study was to compare the predictability of the Vintzileos’ formula with the Hadlock’s formula in estimating the fetal weight nearest to the actual birth weight.
Methods: It was a cross sectional prospective observational diagnostic study conducted with 140 pregnant women with single viable fetus and no major congenital abnormalities. A Two-dimensional ultrasound scan was performed between 38 and 42 weeks gestation and within 24hrs of labor, which measured the biparietal diameter (BPD), head circumference(HC), abdominal circumference(AC), femur length(FL) and thigh circumference(TC) at the level of midthigh, and incorporated them to estimate fetal weight using the Hadlock’s and Vintzileos’ formula.
Results: For the majority of the study population (67.14%), the mean fetal weight estimated by the vintzileos’ formula was nearer to the mean actual birth weight compared to the Hadlock’s formula. There was strong correlation (karl pearson correlation coefficient r=0.822, p<0.001) between sonographically estimated fetal weight by Vintzileos’ formula and the actual birth weight indicating more significant association. There is significant positive correlation between actual birth weight and EFW using Vintzileos’ formula in all categories of birth weights (low, macrosomia and average), the positive correlation increased in macrosomia and low birth weight categories.
Conclusion: The result of this study show that the fetal thigh circumference if incorporated with other standard biometric parameters in estimating fetal weight by ultrasound, improves the predictability of birth weight estimation and can predict intrauterine growth restriction.