We are so conditioned to view conflict as a negative and a problem that needs to be solved. However, arguing can sometimes be a positive element in any relationship, especially a romantic one. It brings recurring issues to the forefront, so that you can address the problem, talk about your feelings, and sometimes just vent so negative feelings and resentment aren't left to fester. In fact, there are some fights you should have when you're new parents, in particular, and trying to adjust to a brand new life with another human being in the mix.
I am always wary of couples that claim that they never fight. While I know everybody, and every relationship, is different, I can't help but wonder that if there's no friction, how can there be any passion? A good argument, much like a good cry, can help to wipe the slate clean and make both parties feel heard. Of course, there are more than a few rules of good behavior when hashing out disagreements. Couples should never resort to name calling or belittling each other, and should try to stick to explaining how they are feeling by using "I" statements, like "I feel" and "I need." And, of course, there's a big difference between a healthy argument and abusive fights, and the latter should never be tolerated.
Having a new baby can be stressful, so it's probably unrealistic to think you'll be able to cruise through those first few difficult months without fighting at all. So try to make sure your fights have a purpose and remember to keep it clean, especially when you're arguing about the following: