Asthma and pregnancy

So my issue is the following, I'm currently at 24 weeks and have always suffered from chronic asthma. I use my inhaler when needed and if necessary my machine ( this is used when my inhaler isn't doing its job).  During the first 4 mths I was fine, using my inhaler probably once every three weeks but now it's on a daily basis.  I'm scared that I'm damaging my babies health by giving him all theses "steroids" but I know that if I can't breathe I must use it.   Do you have any suggestions of a natural route I can take to prevent myself from using my meds?