Sick of being in the middle please help?

My wife and mother got along great before our son was born he's 14 months now, after he was born my mom did said some stuff to my child that she shouldn't have and some stuff she did my wife took the wrong way and now she thinks everything my mother does has a sinister motive behind it. She won't let my mom see my son or let me and him go see her, she won't tell my mom the reason why and she won't let tell either and I'm tired of making excuses. Then I end up with both of them mad at me, I'm the loser in all this and tired of this crap. My wife cut her mom out of her life when she was a child because her mom was abusive and now because my mom said and did a few things (that she has said she sorry for) she wants to cut her out of our lives and I don't think what she did was worth that.How do I put a end to the madness? My wife won't talk to my mom but my mom is willing to talk to her. Help!