Estimativa ponderal fetal ecográfica na gravidez de termo

• Autor(a) principal: Veríssimo, C
• Data de Publicação: 2009
• Outros Autores: Rocha, I
• Tipo de documento: Artigo
• Idioma: por
• Título da fonte: Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos)
• Texto Completo: http://hdl.handle.net/10400.10/128
• topic: Gravidez; Peso fetal; Ultrassonografia pré-natal

Aim: To ascertain the accuracy of ultrasonographic fetal weight estimation in term pregnancy. Population: A total of 446 pregnant women who underwent obstetric ultrasound in our Maternal and Fetal Medicine Unit. Design: Retrospective, transversal, descriptive study. Methods: From the database of ultrasound exams conducted between July 2007 and June 2008, cases were selected if they complied with the following inclusion criteria: singleton pregnancy, absence of malformations, normal amniotic fluid index, complete record of fetal biometries, exam performed between the 37th and 42nd week of gestation by a senior Obstetrician, and delivery of a live newborn within 6 days of the ultrasound. Fetal weight was estimated according to 26 formulas. Results: Mean gestational age at the time of the exam was 38.6 weeks with a standard deviation (sd) of 0.8. Delivery occurred within 3.9 (sd=2.1) days. The most accurate formula for prediction of newborn weight was Hadlock, which revealed an error of 6.2% (sd=5,2%), a Pearson coefficient of 0.81, and 78% of correct estimations considering a +10% error. There were no significant differences in accuracy between the four senior Obstetricians who performed the exam, nor if the subjects were divided according to gestational age. Cephalic presentations rendered more accurate estimations than breech [6.0 (sd=5.2) vs 7.8 (sd=5.1), p = 0.03]. Fetuses with low birth were less accurately estimated than those who were macrossomic [13.3 (sd=5.5) vs 6.9 (sd=5.6), p = 0.03]. Higginbottom and Warsof formulas had the highest accuracy for identification of low birthweight and macrossomic fetuses, respectively. Conclusions: Ultrasonographic fetal weight estimation at term is a relatively accurate procedure, and the Hadlock formula provides the most precise results in fetuses with normal weigh. Breech presentation, low-birth weight and macrossomic fetuses pose specific challenges to this methodology.