Statistical analysis
Normality of the distribution of continuous variables was assessed by
the Kolmogorov-Smirnov test. Numerical data were expressed as mean and
standard deviation (SD) or median and interquartile range (IQR) for
normally and non-normally distributed data, respectively.
The distribution of sFLT-1, PLGF, sFLT-1/PLGF ratio, IL-6, TNF-α,
endothelin and VCAM were logarithmically transformed to approximate
Gaussian distribution. All with the exception of log TNF-α were
converted into multiples of the expected median (MoM) after adjustment
for maternal characteristics. Log TNF-α was not converted to MoMs as
there were no significant independent maternal contributions identified
in the multiple regression model. Between group comparisons were made by
the ANOVA or the Kruskal-Wallis test, with Bonferroni correction for
post-hoc analysis, for normally and non-normally distributed data,
respectively. The Chi-square test was used to compare categorical
variables.
Statistical analysis was performed using SPSS (Version 24; SPSS Inc,
Chicago,IL).