Speaking for my own personal experience, I also was prescribed Vicodin when I was pregnant for migraines, and also for leg pains or rheumatism. I was also prescribed Vicodin after my baby was born for pain, and I was breastfeeding. It is generally considered a "safe" drug. I myself personally and from my knowledge don't honestly believe that the Vicodin caused preterm delivery of the baby. The preterm birth itself has caused the development problems. What caused the preterm birth could be any number of reasons. In time, the child may catch up. Some do, some don't. You just never know. I wish you alll and the baby the best! How old is the baby now? I just love babies!