Jonathan, The problem is more the wet swimsuit favoring the growth of candida that the mother already has. Chlorine is pretty nasty stuff, and if in high enough levels, kills almost any bug. If mom is prone to thrush, she might swim, then change into dry clothes quickly, rather than laying in a wet suit. There is a new swimsuit material that is purported to dry quickly, perhaps that would help. Catherine Watson Genna, IBCLC [log in to unmask] NYC