RESUMO
OBJECTIVE: To evaluate lung growth in healthy fetuses and those with congenital diaphragmatic hernia (CDH) using two-dimensional (2D) ultrasound. METHODS: Fetal right lung measurements obtained by 2D ultrasound between 19 and 37 weeks' gestation were evaluated longitudinally in 66 healthy fetuses and 52 fetuses with isolated left-sided CDH. Right lung areas were determined by the 'tracing' and 'longest-diameters' methods and, subsequently, lung area-to-head circumference ratios (LHRs) were calculated. Functions fitted to these size parameters with respect to gestational age were evaluated for three sets of group-wise comparisons: (1) healthy vs CDH fetuses; (2) different degrees of severity of CDH; and (3) CDH fetuses that survived vs those that died by 6 months postpartum. RESULTS: There was a significantly slower increase in right lung areas and LHRs with advancing gestational age in CDH fetuses than in healthy individuals (P < 0.05). Compared to those with milder forms of CDH, lung areas and LHRs of fetuses with more severe forms displayed a smaller increase (P < 0.05) and LHRs of fetuses with severe CDH did not increase during pregnancy (P > 0.05). Individuals who died postpartum did not show any increase in LHR (P > 0.05) throughout gestation. CONCLUSIONS: The right lung area and LHR, calculated using either the longest-diameters or tracing method, display reduced growth rates during gestation in cases of isolated left-sided CDH as compared with healthy fetuses. The growth curve characteristics of fetal lung areas and LHRs may be useful for predicting neonatal mortality.
Assuntos
Cabeça/diagnóstico por imagem , Hérnias Diafragmáticas Congênitas/diagnóstico por imagem , Medidas de Volume Pulmonar/métodos , Pulmão/diagnóstico por imagem , Ultrassonografia Pré-Natal , Feminino , Idade Gestacional , Cabeça/embriologia , Hérnias Diafragmáticas Congênitas/embriologia , Hérnias Diafragmáticas Congênitas/patologia , Humanos , Pulmão/embriologia , Pulmão/crescimento & desenvolvimento , Valor Preditivo dos Testes , Gravidez , Diagnóstico Pré-Natal , PrognósticoRESUMO
OBJECTIVES: The purpose of this study was to establish reference ranges for 2-dimensional sonographic measurements of fetal lungs from longitudinal data. METHODS: A total of 214 fetal lung measurements were longitudinally evaluated in 62 healthy fetuses between 20 and 36 weeks' menstrual age. Both right and left lung areas were measured in the heart 4-chamber view using lung area tracing and axis diameter methods. Multilevel modeling was used to evaluate the expected values and variability with respect to menstrual age and to generate reference ranges for the lung area, lung-to-head ratio, quantitative lung index, and observed-to-expected lung-to-head ratio for both lungs. RESULTS: The expected values varied with menstrual age for all parameters. Variance was menstrual age dependent for all parameters except the longest diameter area measurements and their lung-to-head ratios. CONCLUSIONS: Models are presented for expected 2-dimensional sonographic lung size parameters and their variance as a function of menstrual age. These data have been used to generate age-specific reference ranges for both measurements and indices.