Complication of insufficient feeding in exclusively breastfed newborns, like hyperbilirubinemia and hypoglycemia are common. The early signs of those complications are frequent or constant crying and prolonged or unsatisfied nursing (where baby latches and unlatches in response to insufficient milk at the breast). These signs are also called the Second Night Syndrome, which put an infant at risk of brain-threatening complications like hyperbilirubinemia, hypoglycemia and hypernatremia if supplementation is delayed or insufficient. The complications are so common they were capture on the first episode of a reality TV show on TLC called “Rattled.”
Lecture on Starvation Jaundice in Dehydrated Exclusively Breastfed Newborns by Baby-Friendly USA, Medical Director
For more information regarding these complications, read a lecture given by Baby-Friendly USA Medical Director, Dr. Lawrence Gartner on the Brain Injury in Dehydrated, Jaundiced Breastfed Newborns.