Adjusting for mean insulin dose per maternal body weight (kg) over gestation, total GWG per kg was associated with non-statistically significant increased odds (aOR = 1.51, [95%CI: 0.96–2.39], p = 0.07) for overweight/obesity among offspring at follow-up. The gene discussed is INS; the disease is obesity due to melanocortin 4 receptor deficiency.