If a newborn receives very few or no calories as nutrition, glucose from the liver is sacrificed in order to keep the other organs alive. Once the glucose supplies inside the body start to run out, it goes into a state of hypoglycemia, or low blood sugar.
The longer the state of hypoglycemia goes, the more cells die inside the body. Severe hypoglycemia also causes brain cell death, which in turn can cause severe problems, which can include permanent disability.
The signs of hypoglycemia in babies that you should watch out for include:
Fussiness, constant rooting, and suckling
Inconsolable crying despite prolonged breastfeeding
Exhaustion or sleepiness
Lethargy, poor feeding, unresponsiveness
Seizures, coma
Hypothermia, low heart rate, and slowing or cessation of breathing