I suffer from recurrent miscarriage. My pregnancies always start out stronger when I use castor oil packs. I don't know if it's because it improves blood flow to the area. I've also heard it can slow the activity of natural killer cells. I have been diagnosed with a genetic blood clotting and my OB suspects that I have an overactive immune system as well which kills my embryos. I do suffer from autoimmune hypothyroidism. I'm working on healing my immune system with natural remedies before doing the testing for immune-related pregnancy loss. I definitely will be using castor oil packs whenever I start trying to conceive again!
My mother drank a bottle of castor oil when she gave birth to me because it took so long time and she was in a lot of pain. That was a couple of years ago now and they don't use that regularly anymore(no money for industry)