The correlation between lung volume and liver herniation measurements by fetal MRI in isolated congenital diaphragmatic hernia: a systematic review and meta-analysis of observational studies.

ABSTRACT

OBJECTIVE: We conducted a meta-analysis to assess the correlation of lung volume and liver position measured by magnetic resonance imaging (MRI) with survival until discharge in fetuses with isolated congenital diaphragmatic hernia (CDH). METHOD: Systematic searches of MEDLINE and EMBASE from 1 January 1980 to 10 December 2010 were performed. Studies correlating total fetal lung volumes (TFLV, observed/expected (O/E) TFLV) and/or liver position by fetal MRI to survival in expectantly managed fetuses with CDH were included. Data on the side of the defect, position of the liver, TFLV, O/E TFLV, gestational age (GA) at MRI, GA and weight at birth were collected. Odds ratio (OR) for dichotomous data, mean differences (MD) or standardized mean differences (SMD) for continuous variables were determined using RevMan 5.0 software. RESULTS: Nineteen studies (n = 602 fetuses) were included. Survival was associated with left-sided defects (OR 2.52; p = 0.01), "liver down" (OR 0.18; p < 0.00001), a higher TFLV (MD 9.63; p < 0.00001) and O/E TFLV (SMD 0.98; p < 0.00001) as well as higher birth weight (MD 146.60; p = 0.04). GA at MRI (MD 0.70) and GA at birth (MD 0.33) were not correlated with survival. CONCLUSIONS: MRI measurements of fetal lung volumes, liver position and side of the defect correlate well with neonatal survival in fetuses with isolated CDH.