Statistics
Data were analyzed with Prism for Windows version 7.0 (Graphpad Software, San Diego, CA, USA) and Analyze-it (Analyze-it for Microsoft Excel 4.81.4; Analyze-it Software, Leeds, UK). Data were checked for normality using the Shapiro Wilk test for normality. All data are expressed as mean ± standard deviation or median (interquartile range) depending on normality; sub classifications were illustrated as number (percentage). Regression analysis of the different variables (TCD, Skull and brain BPD, skull and brain FOD, atrial width, calculated HC and extra-axial CSF, total grading score and the different volumes) in normal fetuses allowed calculation of normal ranges for each parameter. Differences between the CDH population at the first and the second time point and the controls were studied with the Wilcoxon-Mann-Whitney test, using the observed/expected ratios, which controls for gestational age at imaging. To analyze the evolution over time, a Wilcoxon hypothesis test was performed on the difference in observed/expected ratio between the second and first time point. Correlations were assessed using Pearson’s correlation coefficient and Bonferroni correction for multiple comparisons was made.