A case of an infant who had morphine exposure during and following pregnancy while her mother was treated with intrathecal (i.t.) morphine is presented along with a review of the relevant literature. Successful maternal pain management was achieved during pregnancy and while breastfeeding. Minimal maternal serum and breast milk levels in the first 7 postpartum weeks were found. Also, infant sleep and arousal behavior and general development at 2 and 7 months were unremarkable, illustrating the possible safe and efficacious use of i.t. morphine during and following pregnancy. Further work is required to understand opioid pharmacology during breastfeeding, which will be used to develop an empirical approach to breastfeeding and morphine use.