I can't be 100% certain, but I believe there is a link between developing thrush and using these soothies. I used these for the first couple weeks of nursing. I never used a set for more than 2 days. After about 2-3 weeks both me and my baby developed thrush. We took medication to clear the thrush, I switched to cotton nursing pads, and all seemed to return to normal. However, I ran out of cotton nursing pads and used these for about 12-hours. Within two days of using these again all of the thrush symptoms and pain returned for me.
It could be coincidence.... Or these might be contributing to my thrush development. My thought is that these keep my nipples moist, dark, warm, and hold milk against the skin (I leak a lot)...this is the perfect breeding ground for yeast.