Andrea, I assume the mother with the ill baby is, herself, healthy? Then, I won't say what I truly think of the MD's comment that co-sleeping is a cause of pneumonia, except to tone it down and remind you that those of us who are not MD's are expected to be patient(s). A giant vial of patience pills should be standard issue for all of us, eh? Good grief. Is anyone keeping track of how many chapters we have at this point of "stupid reasons to stop...[breastfeeding, co-sleeping, eating beans, etc.]?" I think someone else mentioned this a few weeks ago, but in my internet forays I found what *appeared to be* at first glance a very good resource @ http://www.surgery.uiowa.edu/prbr.html It advertises, with excerpts, an article from the American Journal of Surgery Volume 170; October 1995, pages 401-405, titled "Diagnosis and Management of Breast Problems During Pregnancy and Lactation." I invite all of you with internet on-ramps to take a look at this page yourselves. The surgeon who wrote the article writes that breastfeeding from a mastitic breast is "reported to cause pneumonia in the infant and should be avoided." No mention of co-sleeping, but these ideas often spring from the same well of misinformation. This breast surgeon also writes that mastitis generally occurs during the first month post-partum and is most "likely to affect young, inexperienced mothers who do not practice proper hygiene." My own analysis (note I never use IMHO because everyone sniggers at the H) is that most of us are so overly careful to be 100% certain of our information before we own it, before we share it. When we are faced with the self-assured, boldly pronounced, WRONG info it shocks us. I have never met a group of health care professionals who are so very fastidious in fact finding as are Lactation Consultants! Do you think this is because our profession is one which requires us to daily hack away at the overgrowth of misinformation and myth? Pass the patience pills, please. I'm going for a walk now. Margery Wilson, IBCLC Cambridge, Massachusetts