Consistent with this hypothesis, in the German GDM Study, Ziegler et al. reported that the protective effect of lactation was not present in women who required insulin during pregnancy (HR 0.81, p = 0.4) compared to those with diet-controlled GDM (HR 0.46, p = 0.014) [12], suggesting that the severity of insulin resistance or β-cell dysfunction during pregnancy might modify the relationship between lactation duration and progression of dysglycemia. Here, INS is linked to gestational diabetes.