Most Helpful Guy
A lot of guys panic just after the baby comes. He knows life will never be the same, you will never pay him as much attention, there'll be much greater pressure on him, more responisbility.
A lot of guys run for it at this time.
See if you can get him to agree to a trial period of adjustment to the new lifestyle. Ask him to hang in there a few months and then see how he feels.
Sometimes guys need to get over the urge to run away!
But I'm not going to kid you, he might well still want to run away after a few months. But after 6 years, I'd sure try everything to get him to calm down. Relationship counseling, getting his parents to talk to him..whatever you can think of.