Hi, if your child has good relationships with the people you are leaving him with then there shouldn't be a problem as long as there is enough communication between yourself and your child. It is important for you and the father as well to take time out of your day to call or facetime your kid and allow your child to talk to you, and if in any moment your child implies that he is not comfortable, then you must take action. Kids really only will feel neglected if you ignore or try to act like their concerns aren't justified, no matter how small a child is, you must always make sure they are able to open up to you and feel safe with you. With that being said, there shouldn't be a problem as long as you sit with your child and try to explain until he understands that you will be leaving for a year. Also whenever you have any holidays, go visit your kid.