Hi M.,
My sister has a titanium rod in her back after a surgery to correct scoliosis. During pregnancy she had some back pains when sitting or standing for too long, releived by rest. It started after 4 or 5 months of pregnancy and lasted until delivery. She also gained a lot of weight during pregnancy so hurd to say was it pain from postoperative state or just from increased body mass.
Regarding delivery, she was told that epidural would be more risky because she can't bend, and she didn't want epidural anyway, so she did natural delivery. Those are the only 2 limitations she had from this rod regarding her pregnancy and labor. Delivery was in Altha-Bates in Berkeley, done by midwife without doctor assistance. I do not know any doctor who specializes in delivery with rod in the back and I guess this condition doesn't really cause any limitations for delivery other then described above. Since there are other means of pain control available, so it is ok to do without epidural. Best wishes to your friend.