My baby nephew is 1 mo.old & has an underdeveloped pituitary gland.can you(in laymans terms)explain what it means & what may lay ahead caring for him?

Several things: An underdeveloped pituitary can be in isolation or in combination w other facial, bony + brain defects as the part of a syndrome. He wiill most likely have issues with growth and development and his ability to learn. Most likely he will be seen by a group of specialists including a geneticist, neurologist, endocrinologist + developmental pediatrician. He may need medication.