One thing to bear in mind is that if your issue is connected with an auto immune problem, pregnancy often "cures" the problem.
I was going to say the same thing. I have multiple sclerosis, and I have been told that when pg it sould go into "remission"... I have also heard that prednisone is given to pg MS ladies during pregnancy, and often prior to giving birth if required, but have not yet had to put that to the test...

Good luck with your arthritis and working out a treatment...
xo