If it's that much of a concern. You should break up with him. I was with relationship with few women in my life time. I told them i stutter. They slowly started to pull away. Its in your woman's intuition to bare children with no disabilities. Even though I was hurt. I totally understand. Living life with a speech impediment. You don't allow yourself to dream. Because you know it will hold you back. Unless you are willing to work with your kid(s). Most parents with kids who stutter. Don't do anything about. Like my parents. Like sending their children to a speech therapist.