Army Nurse Corp and Child custody

Hello all. I have been accepted into the Army nurse corp(Active) in Jan. Scheduled to go to OBLC in October. I am a single father with a six year old that lives with his mother. Just wanted to get clarification on custody with respect to the Army standards. I was informed that if I join the military that I woould have to sign over full custody to the primary caregiver? Is this correct. Please advise.