Congenital diaphragmatic hernia: an evaluation of the prognostic value of the lung-to-head ratio

Abstract

A retrospective analysis of the prognostic significance of the lung-to-head ratio (LHR) on the outcome of fetuses with left-sided congenital diaphragmatic hernia (CDH). A total of 12 fetuses with isolated left CDH without any chromosomal abnormalities were included in this study. Twelve LHR measurements could retrospectively be calculated from the last available ultrasonographic recordings before birth. The relationship between the LHR and fetal outcome and gestational age was investigated. The cutoff levels as previously published were applied to determine their predictive value in this population. The association between other prenatal predictive variables and the fetal outcome was also determined. Survival was defined as being discharged from the hospital. The overall survival rate was 75%, and a statistically significant difference was observed between the mean LHR of the survivors and the mean LHR of the nonsurvivors (1.81 vs. 0.43), whereas the mean gestational age of these two groups did not differ. The LHR was not gestational age dependent with regard to its ability to predict the fetal outcome. The cutoff levels LHR <1, 1-1.4, and >1.4 showed good applicability for predicting fetal outcome within the present study population, with 100% survival if LHR >1.4 and 75% mortality if LHR <1. The intrathoracic position of the stomach, mediastinal shift, and polyhydramnios as individual variables and early diagnosis (<25 weeks gestation) all turned out to be poor sonographic predictors of fetal outcome. The LHR proved to be a good predictor of fetal outcome, independent of gestational age at the time of measurement. To further substantiate our observations, a prospective multicenter study is warranted.