Younger Narc?

My narc is 18, only ten months younger than I. His mother claims that he and his sister, are both ADD. Something that his dad also has. She is also very enabling. She's that mother that loves her kids so much, especially her son, that she practically does everything for him. She gives him money, prepares all his food, EVERYTHING pretty much. My question is, do narcs progress over time? Meaning, do they get worse with age, or could it be possible that he has reached his full potential already? I ask because I'm pregnant with his baby, and throughout our relationship he has shown times of sincerity but, the more I read on narcissism and their qualities, everything just makes more sense. He was dating a FAR older woman before I, and when I got in contact with her, she's the one that brought it up. She's suffered from his physical, emotional, and mental abuse for the past 3 years. I've only been around for the past year, and although he has been emotionally abusive and manipulative, he's never been REALLY physical with me. Could he get worse with time, and is there a possibility that he could change NOW?