R studio statistical software

Data are reported as mean (±SD or SEM) or median (interquartile range) for continuous variables and as number (percentage) for categorical variables. The normality of continuous variables was assessed using the Shapiro-Wilk W test. For the comparison of continuous variables between 2 groups, an unpaired t test or Mann-Whitney U test (in case of non-normal distribution) was performed. For the comparison of categorical variables between 2 groups, Fisher exact or χ² test was applied. We used linear mixed models to evaluate the longitudinal course of the angiogenic markers according to treatment group. To account for within-subject correlations, a random intercept for study subject was used. Time (days at which blood was taken) and GA at the first measurement were added as fixed effects. Baseline values (at day 0) were added as covariate. For the placenta studies, differences in sFlt-1 levels were studied using general linear model repeated measurements. A P<0.05 was considered statistically significant. Data were analyzed using IBM SPSS statistics (IBM Corporation, version 25) and R studio Statistical Software.