I was told that - basically - the theory is that it may not be fantastic for the fetus to get some medication, but that it's really bad for the fetus if the mother isn't getting enough oxygen. That being said, I imagine that some drugs are OK and others are not. I'd ask my doctor about it.
I took an inhaler for about 3 weeks earlier in my pregnancy (I'm almost 30 wks now!), and now I'm taking Claritin (over the counter strength) for seasonal allergies.
I am pregnant and have bad allergies and asthma. I tried to go the first couple of weeks without any meds... in spring.... couldn't do it! I was miserable. Benadryl is always ok, and my doctor said ok to taking Singulair (that is what I took prior to conceiving) I use my inhaler as needed (once a week maybe)
What did you take for allergies and asthma prior to being pregnant?
Good luck.