my friend is pregnant and and we were thinking. shouldn't the baby be considered present because he is human and technically is in the classroom?
No because it is highly unlikely the baby is on the attendance list. This "present" situation is not about whether someone as a human is present in the room, but it is more about keeping track of those that should be present from the attendance list and is actively participating in the class.
So unless the unborn baby can answer for him/herself that they are present and are going to actively participate in class the "present" answer is not applicable.