Developmental disorders are groups of psychiatric conditions.
How do they occur, what is there to know about them?
It can be language, learning, or motor disorders from birth.
Really is it casued from natural defects or from things like the mother not taking care of herself or what?
It can actually be both. Normally they are present in Early life
Thats terrible, is there any way to treat or avoid them?
Normally it is actually genetic. 
That awful, well thanks for all the information to show me what to expect or avoid.