My husband seems to end his relationships with women whenever he has an infant

My husband and I would've been married for five years come June 2016. Our infant daughter just had her birthday. Shortly before, he told me he wanted a divorce. He has four other children, three of which are from his first wife. He decided to end that marriage when his youngest was an infant. The children do not have a good relationship with him now. He has another child from a woman he was dating. He decided he didn't want to be with her anymore when the child was an infant. It seems to me that there is a pattern. He easily detaches from relationships at the same time in the child's life but wants a relationship with them when they are older. I've tried to research online, but I'm not getting any answers. He also has an unhealthy dependency on alcohol and does not believe in mental health disorders such as depression and bi-polar disorder. He also does not believe in therapy or seeking help from professionals. Is there a detachment disorder or some form of mental block he could have? Where do you recommend researching this?