We asked if fetal lung-to-head ratio (LHR) of 1.0 or lower or liver herniation had a statistical effect on survival or need for extracorporeal membrane oxygenation (ECMO), compared with LHR above 1.0 in patients with congenital diaphragmatic hernia (CDH).
Methods: Antenatal records of all patients diagnosed with CDH from January of 2002 to June of 2005 were examined. Inclusion criteria were isolated left-sided CDH and absence of significant cardiac or other anomalies/syndromes, treated solely at this institution. Lung-to-head ratio values were compared based on the value currently proposed for fetal intervention: LHR of 1.0 or lower vs LHR above 1.0. Outcome was assessed as survival (discharge to home) or need for ECMO.
Results: Twenty-eight patients met inclusion criteria. Overall survival was 86% (24/28). Postnatal survival in fetuses with LHR of 1.0 or lower (8/11) was not statistically different from LHR above 1.0 (16/17) (73% vs 94%, P = .114). The need for ECMO in the group with LHR of 1.0 or lower (3/11) was not significantly different from those with LHR above 1.0 (1/17) (27% vs 6%, P = .114). Herniation of the fetal liver into the chest did not affect survival or need for ECMO (P = .228).
Conclusion: Neither LHR of 1.0 or lower nor liver herniation identified a risk factor significant enough to warrant fetal intervention. Multicenter studies may be more appropriate to investigate this clinical problem.