Is prematurity associated with neonatal mortality in severe isolated congenital diaphragmatic hernia after fetal tracheal occlusion?

OBJECTIVE: Fetoscopic tracheal occlusion (FETO) has been indicated for severe isolated CDH. However, this fetal intervention is related with prematurity (mean gestational age at delivery 35 weeks). In this study, we sought to evaluate if prematurity was associated with mortality after FETO. STUDY DESIGN: This is a prospective cohort study of 35 fetuses with severe isolatedCDHthat underwent FETO between 26-30 weeks. Preterm birth (<37 weeks) and extreme preterm birth (<32 weeks) were analyzed according to neonatal mortality using Fisher exact test. Other variables were also evaluated such as the lung-to-head ratio (LHR) prior to FETO, gestational age at FETO, duration of tracheal occlusion and duration of the procedure using t-test and Man-Whitney U test. RESULTS: Survival rate after FETO was 54.3%. Mean gestational age at delivery was 35.9±2.4 weeks in survivors and 34.9±2.8 weeks in those that died (p=0.28). Preterm birth and extreme preterm birth were not associated with mortality (p= 0.51 and p=0.34, respectively). The only variable associated with mortality was the LHR prior to FETO (0.73±0.02 vs. 0.84±0.09; p<0.01). CONCLUSION: In the present cohort of fetuses with severe CDH that underwent FETO, preterm birth and extreme preterm birth were not associated with mortality. The LHR prior to FETO can be used to predict outcome after tracheal occlusion performed between 26-30 weeks.