Predicting neonatal deaths and pulmonary hypoplasia in isolated congenital diaphragmatic hernia using the sonographic fetal lung volume-body weight ratio.
OBJECTIVE
The objective of our study was to evaluate the potential of the sonographic fetal lung volume-body weight ratio to predict neonatal deaths and pulmonary hypoplasia in fetuses with isolated congenital diaphragmatic hernia (CDH).


METHODS
Between January 2002 and December 2004, 40 fetuses with isolated CDH and 450 control subjects were prospectively evaluated in two centers. Fetal lung volumes were estimated on 3D sonography using the rotational technique and fetal weight on 2D sonography using the Hadlock equation. The ratio of sonographic fetal lung volume to body weight was calculated in each case and was correlated with neonatal deaths using the Mann-Whitney U test. Accuracies of the ratio in predicting neonatal deaths and pathologic diagnosis of pulmonary hypoplasia were also evaluated.


RESULTS
The ratio of sonographic fetal lung volume to body weight is constant throughout gestation, with a mean value of 0.025. The ratio was significantly lower in neonates that died (median, 0.009; range, 0.004-0.021) than in those that survived (median, 0.011; range, 0.008-0.020) (p = 0.018). Pulmonary hypoplasia was suspected prenatally in 34 of 40 (85.0%) fetuses with CDH, in all cases of death (100%), and in seven of nine (77.8%) neonates that survived. At autopsy, pulmonary hypoplasia was diagnosed in 19 cases (86.4%). Accuracies of the ratio in predicting neonatal deaths and pulmonary hypoplasia were 64.5% (20/31) and 86.4% (19/22), respectively.


CONCLUSIONS
The sonographic fetal lung volume-body weight ratio can be used more accurately to diagnose pulmonary hypoplasia than to predict neonatal deaths in fetuses with isolated CDH. Further studies are necessary to show the prevalence of pulmonary hypoplasia in fetuses with isolated CDH and its importance for predicting neonatal deaths.
Ruano
Rodrigo
R
Department of Obstetrics, Instituto Central do Hospital das Clinicas da Faculdade de Medicina da Universidade de São Paulo, Av. Dr. Enéas de Carvalho Aguiar, 225-10o andar-Sala 10.085, São Paulo, Brasil CEP 05403-000. rodrigoruano@usp.br
Aubry
Marie-Cecile
MC
Dumez
Yves
Y
Zugaib
Marcelo
M
Benachi
Alexandra
A
D016022:Case-Control Studies; D015331:Cohort Studies; D020567:Fetal Weight; D005865:Gestational Age; D006548:Hernia, Diaphragmatic / Q000000981:diagnostic imaging* / Q000401:mortality; D065630:Hernias, Diaphragmatic, Congenital; D006801:Humans; D007226:Infant Mortality; D007231:Infant, Newborn; D008168:Lung / Q000002:abnormalities* / Q000000981:diagnostic imaging*; D008176:Lung Volume Measurements; D009929:Organ Size; D011237:Predictive Value of Tests; D016216:Ultrasonography, Prenatal