I was better during pregnancy. Of course, I don't know if that was due to the fact that I was carrying twins and was high risk, so I spent much of the time lying around. I did feel sick most of the time, but not mast cell sick. For me twin pregnancy was just hard I guess. At the time, I was not diagnosed and not on ANY antihistamines or meds. The only thing I had trouble with (vomiting) was my spinal anesthesia for my C-section. I presume that is because I was not on any antihistamines and anesthesia can bother some of us. Had I been on the normal preventatives for that, I imagine that would have helped.

I would suggest asking a mast cell specialist about what meds can be safely taken during pregnancy.

I have been pregnant twice since changing my diet and taking (some) drugs for this condition.  My strict diet made me the most nervous, to be honest.  I didn't know if I could get enough calories and nutrients.  I was able to take a prenatal vitamin and everything was fine.  I was taking asthma meds and antihistamines (dr. switsched me to med safe for pg).  I felt better than I had in years during my 2nd and 3rd trimesters.  Mine is autoimmune and that is probably why I felt better, though.   Even with having to take prednisone a few times, using inhaled meds daily and antihistamines and rescue inhalers (the first of these two pregnancies was worse - not sure why - very ill) the babies were both born healthy - healthy sizes (7.4 - 8.5lbs) .