Avaliação da estimativa do peso fetal através da ultrassonografia tridimensional

Abstract

The perinatal risks of changes in fetal growth are well established both in cases of macrosomia as in cases of fetal growth restriction. Birth weight is therefore an important predictive parameter of perinatal morbidity and mortality and its correct evaluation, an important tool of good obstetric practice. Several formulas using two-dimensional parameters have been proposed, with an error margin ranging between 7-10%, reaching 14%. The objectives of this research were to evaluate fetal weight estimation measured by three-dimensional ultrasound compared to two-dimensional ultrasonography in the general population. We performed a clinical trial diagnosis with 49 pregnant women followed by the Perinatal Center of Obstetrics Service of the Pedro Ernesto University Hospital. Fetal weight was estimated by performing two-dimensional and three-dimensional ultrasonography, by the same examiner on the same occasion, in pregnant women whose delivery occurred at the Perinatal Center within 48 hours after the examination. Estimates obtained by two- and three-dimensional examination were compared with birth weight. The Shapiro-Wilk test was performed to evaluate the normal distribution of data. The comparison of different formulas of fetal weight estimation with the birth weight was performed using the Wilcoxon test,. Comparison of different formulas each other was performed using the Kruskal-Wallis test. The results showed no statistically significant difference between fetal weight estimation performed by two-dimensional and three-dimensional ultrasonography in the whole group (Wilcoxon: USG2D p-value = 0.86; USG3D p-value = 0.24; USG2D3D p-value = 0.10 ; Kruskal-Wallis: p-value = 0.18). The assessment of intra-observer variability of the method using only the thigh volume fraction showed a concordance of 90% and the method using two-dimensional and three-dimensional parameters showed a concordance of 96%. In the case of inter-observer variability this agreement were respectively 90 and 96%. It was concluded that there is no statistically significant difference between the estimated fetal weight accomplished through the use of two-dimensional ultrasound and performed by three-dimensional ultrasonography in the general population. Future studies should provide knowledge in the pursuit of association between changes in fetal muscle and soft tissue compartment and changes in fetal growth, helping to build individualized models of the fetal nutritional status.