Susan, I don't have any information on your particular question, but can share my own experience. Keeping in mind that stress and fatigue can trigger asthma attacks, I used to wheeze while breastfeeding, but only in the evening when I was tired. During the night, and earlier in the day it was no problem. We never did figure out any other trigger than fatigue. Margaret K.K. Radcliffe [log in to unmask] Dept. of Mining & Minerals Engr. Virginia Tech, Blacksburg, VA