Congenital diaphragmatic hernia: an evaluation of the prognostic value of the lung-to-head ratio and other prenatal parameters.

Objectives: A retrospective analysis of the prognostic significance of the lung-to-head ratio (LHR) and other prenatal parameters on the outcome of fetuses with left-sided congenital diaphragmatic hernia (CDH).
Methods: A total of 26 fetuses with isolated left CDH without chromosomal abnormalities were included. Twenty-one LHR measurements could retrospectively be calculated from the last available ultrasonographic recordings before birth. The relationship between LHR and fetal outcome and the gestational age dependency of this relation was tested. Cutoff levels as previously published were applied to determine their predictive value in this population. The association between other prenatal predictive variables and fetal outcome was also determined. Survival was defined as discharge from the hospital.
Results: The overall survival rate was 50%. There was a statistically significant difference between the mean LHR of the survivors compared to the mean LHR of the nonsurvivors (1.78 vs 1.02), whereas the mean gestational age of these two groups did not differ. LHR was not gestational age dependent in the prediction of fetal outcome. The cutoff levels LHR <1, 1-1.4, >1.4 showed a good applicability in the prediction of fetal outcome within the present study population with a 100% survival if LHR >1.4 and a 100% mortality if LHR <1. An intrathoracic position of the stomach, mediastinal shift, polyhydramnios as individual variables and early diagnosis (<25 weeks' gestation) revealed to be poor sonographic predictors for fetal outcome.
Conclusion: LHR proved to be a good predictor for fetal outcome, independent of gestational age at the time of the measurement. To substantiate our observation, a prospective multicenter study is warranted.
(Copyright 2003 John Wiley & Sons, Ltd.)