Prior observational studies have inferred epidurals negatively affect breastfeeding by decreasing maternal plasma oxytocin release which may adversely affect infant neurobehavioral development. In a study by Beilin et al., it was reported that mothers receiving a high cumulative dose (> 150 microgram) epidural fentanyl were more likely to have stopped nursing 6 weeks postpartum compared with groups receiving no fentanyl or those receiving < 150 microgram. The study however, was underpowered to detect differences in breastfeeding prior to hospital discharge. In addition, the breastfeeding assessment tool utilized resulted in binary assessments, and therefore, a global rating of the quality of breastfeeding was not available.