Stress (physical and emotional) can trigger autoimmune diseases, but childbirth is a special case. My understanding is that when you have a baby--whether by C-Section or not--you're especially prone to infection. Your body responds by creating all sorts of antibodies to protect you. This heightened state of the immune system (I know this is vague) makes certain people prone to developing an autoimmune disease. I came down with Graves' after the birth of one of my children, and I'm told that's quite common.

Abby