BACKGROUND: Hospital practices supportive of breastfeeding can improve breastfeeding rates. There are limited data available on how improved hospital practices are associated with hospital costs. We describe the association between the number of breastfeeding supportive practices a hospital has in place and the cost of an uncomplicated birth.METHODS: Data from hospitals in 20 states that participated in the 2007 Maternity Practices in Infant Nutrition and Care (mPINC) survey and Healthcare Cost and Utilization Project's (HCUP) State Inpatient Databases (SID) were merged to calculate the average median hospital cost of uncomplicated vaginal and cesarean section births by number of ideal practices from the Ten Steps to Successful Breastfeeding. Linear regression analyses were conducted to estimate change in birth cost for each additional ideal practice in place.RESULTS: Sixty-one percent of hospitals had ideal practice on 3-5 of the 10 steps, whereas 29 percent of hospitals had ideal practice on 6-8. Adjusted analyses of uncomplicated births revealed a higher but nonsignificant increase in any of the birth categories (all births, $19; vaginal, $15; cesarean section, $39) with each additional breastfeeding supportive maternity care practice in place.CONCLUSIONS: Our results revealed that the number of breastfeeding supportive practices a hospital has in place is not significantly associated with higher birth costs. Concern for higher birth costs should not be a barrier for improving maternity care practices that support women who choose to breastfeed.