LEP and diabetes mellitus: Concentrations of maternal serum IGF-I (Holmes et al., 1997) and leptin (Yildiz et al., 2002) are decreased in intrauterine growth restriction (IUGR) while pregnancies associated with obesity and diabetes have higher maternal serum IGF-I, insulin, and leptin (Lauszus et al., 2001; Jansson et al., 2008).