In human IUGR, maternal serum concentrations of IGF-I, insulin, and leptin are decreased (Jansson et al., 2006) while obese pregnant women and pregnancies complicated with gestational diabetes have higher serum levels of leptin, insulin, IGF-I, and decreased levels of adiponectin (Lauszus et al., 2001; Jansson et al., 2008; Aye et al., 2013a, 2015). Here, LEP is linked to fetal growth restriction.