Maternal glucose crosses the placenta while insulin does not (remember that HPL services the baby by shunting the mother's glucose to the baby by conferring insulin resistance to the mom). In response to hyperglycemia in the mom, the fetal pancreatic islet cells increase the production of insulin. If the source of glucose is quickly removed, such as after delivery, the infant has a high risk of developing hypoglycemia, which can lead to convulsions and death.