A large number of women are treated for pain following cesarean section or episiotomy. It is important to effectively treat postpartum pain. Codeine is widely used for postpartum pain, mostly in combination with acetaminophen. Tylenol No. 3 is the most common codeine-acetaminophen combination in clinical use. Recent research from Motherisk suggests that codeine might not be safe for all breastfed infants, as in a minority of cases it might cause CNS depression and apnea. A minority of mothers might convert more codeine to morphine in their bodies, putting their babies at risk of side effects or even death. Infants appear to be more sensitive to the effects of narcotic opioids, such as morphine, than older children or adults.

CNS—central nervous system.