Studies of the human placenta have reported perturbations in the regulation of the Igf2-H19 locus and alterations in the expression/abundance of Igf2 signalling factors and placental hormones in pregnancy complications including gestational diabetes, fetal growth restriction and large for gestational age (Laviola et al., 2005; Le et al., 2013; Liao et al., 2017; Ngala et al., 2017; Su et al., 2016). This evidence concerns the gene H19 and gestational diabetes.