CDKN1C and fetal growth restriction: Multivariate analysis by direct logistic regression (dependent variable: IUGR yes/no) was performed to rule out the effect of confounding variables with an effect on CDKN1C expression in our sample (primiparity and ART); we also included pre-eclampsia as a covariate, as it was the only clinical feature with a different prevalence between the IUGR and control groups (prevalence of 22.2% vs. 3.8%, Chi-square test p = 0.01).