Upon multivariate analysis (adjusting for age, parity, race, GDM, insulin sensitivity, gestational age, baby gender), excessive GWG categorized by Caucasian BMI cut-offs was associated with increased risk of macrosomia (adjusted OR 8.65, 95% CI 1.07–70.01), NFM >90th centile (adjusted OR 2.14, 95% CI 1.02–4.45) and SSFT >90th centile (adjusted OR 3.88, 95% CI 1.77–8.51). The gene discussed is INS; the disease is Large for gestational age.