Prednisone/prednisolone may be a steroid, but I believe that it's not one that crosses the placenta.

For what it's worth, I was on prednisone right through my pregnancy, but never more than 10mg per day. It's often used to treat some conditions which cause miscarriage.

I know what I'd do if it were me, but certainly don't want to pressure you into doing something you're not comfortable with.