INS and Hyperglycemia: In particular, identifying whether the fetus has inherited a GCK variant from either the mother or father can be important for tailoring care during pregnancy: in a pregnancy where the fetus has a GCK variant, hyperglycemia in the mother should usually not be treated as it can lead to dangerously low birthweight, while treatment with insulin is more likely to be indicated if the fetus did not inherit the GCK variant [24].