I would think that with proper positioning that the damage to the nipples
would have a chance to heal and the pain that occurs from this sort of
positioning would decrease. However, as for the inner type nipple pain
this mom describes, it is possible that the sensitivity will not go away
until after birth. I tandem nursed throughout my last pregnancy, and
experienced nipple pain/sensitivity from the 3rd month on that was severe
enough that I had to limit nursings.  To my amazement and joy, this pain
disappeared immediately after I gave birth.

Ione