Upon multivariate-analysis (adjusting for age, parity, race, GDM, insulin-sensitivity, baby-gender) excessive GWG categorized with Caucasian BMI cut-offs was significantly associated with increased risk of macrosomia (adjusted odds ratio (aOR) 8.65, 95% confidence interval (CI) 1.07–70.01), Neonatal-Fat-Mass (NFM) >90th centile (aOR 2.14, 95% CI 1.02–4.45) and Sum-of-Skinfold Thickness (SSFT) >90th centile (aOR 3.88, 95% CI 1.77–8.51). The gene discussed is INS; the disease is gestational diabetes.