PECAM1 and gestational diabetes: HBC-related gene expression correlated positively with the endothelial marker PECAM1/CD31, in both non-GDM and GDM placentae (r ≥ 0.5, p < 0.05).<h4>Conclusions</h4>HBCs abundance is reduced in GDM placentae independently of fetal growth or sex, whilst HBC phenotype is preserved.