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.