Through the yrs that I've been a member of this site I've heard a few moms mention that they concieved shortly after being off IVs. They seemed to believe maybe there was tie like maybe being healthier from the IVs or the IVs indirectly had thinned their cervical mucus. Also, one should note that often people gain weight while on IVs (bc they are healthier) and therefore may be more able to conceive. As christian made note to stability of FEV1 so should your weight bc it will only be harder to gain weight while pregnant than before.