Background: Fetuses with congenital diaphragmatic hernia (CDH) are at risk of death from pulmonary hypoplasia at birth.
Objective: To determine the value of prenatal imaging parameters for predicting lethal pulmonary hypoplasia in fetuses with CDH.
Search strategy: Relevant papers were identified by searching MEDLINE (1966-2008), EMBASE (1988-2008) and the Cochrane Library (2008 issue 3).
Selection criteria: Selected studies examined diagnostic tests for the prenatal prediction of lethal pulmonary hypoplasia in fetuses with CDH. The primary outcome measure was perinatal survival.
Results: Twenty-one studies fulfilled the entry criteria, of which six examined entirely unique heterogeneous parameters and the remaining 15 examined lung-head ratios (LHR) and/or the presence of liver in the fetal thorax. The strongest association was that of LHR > or = 0.6 compared to <0.6 (OR: 17.02; 95% CI: 2.10-137.89), although more clinically relevant was that of LHR >1.0 (OR: 5.07; 95% CI: 2.94-8.74). The finding of liver in the fetal chest was a poor prognostic feature (survival OR: 0.32; 95% CI: 0.21-0.49).
Conclusion: In CDH, LHR and the presence of liver in the fetal thorax may be a useful predictive indicator of perinatal survival. Future usage of developing techniques needs careful evaluation prior to usage to guide therapy.