Percent predicted lung volume changes on fetal magnetic resonance imaging throughout gestation in congenital diaphragmatic hernia

Purpose Percent predicted lung volume (PPLV) < 15% on fetal MRI predicts high-risk CDH. Potential changes in PPLV throughout gestation and impact on risk stratification are unknown. We reviewed CDH patients with serial fetal MRIs to follow PPLV and determine correlation with postnatal outcomes. Methods CDH patients with serial fetal MRIs from 2005 to 2015 were included. We recorded prenatal MRI gestational age (GA) and PPLV, postnatal ECMO use, and survival. Data were analyzed by logistic regression and Fisher's exact test. Results 57 patients had 127 fetal MRI studies. PPLV decreased from mean 25.4% to 19.6% between GA 22.1 and 32.6 weeks. A steeper decline in PPLV, regardless of final PPLV, was independently predictive of higher ECMO use (p = 0.046) and death (p = 0.045). All patients with first PPLV < 15% remained high-risk with poor outcomes. Of those with first PPLV > 15%, 31% dropped below 15%, having similar ECMO use as the high-risk cohort, but trending toward greater survival (p = 0.09). Those with first and final PPLV > 15% had significantly less ECMO use (p = 0.015) and greater survival (p < 0.001) than the high-risk cohort. Conclusions On average, PPLV decreases throughout gestation in fetuses with CDH. Serial MRI is recommended for those with initial PPLV > 15%, as clinical outcomes tend to mirror the lowest PPLV. Type of study Treatment study Level of evidence III