Data from the 2015 Maternity Practices in Infant Nutrition and Care (mPINC) survey of all U.S. maternity facilities, linked with postal code–level race data from the U.S. Census, found that hospitals in areas with higher percentages of black residents reported lower percentages of infants in the neonatal intensive care unit (NICU) routinely receiving mother’s own breast milk (median = 72.0%) or banked donor breast milk (median = 5.0%) than did hospitals in areas with lower percentages of black residents (median = 80.0% and 10.0%, respectively).

Breast milk is the recommended nutrition for infants, and is particularly beneficial for preterm infants. Non-Hispanic black mothers are at increased risk for preterm birth, and also have lower breastfeeding rates. Some data suggest there might be limited access to donor milk, which is recommended for preterm and other high-risk infants when mother’s milk is unavailable.

Breast milk is the recommended nutrition for infants. For preterm infants, when mother’s milk is not available, pasteurized donor milk is recommended (1). Non-Hispanic black mothers are at increased risk for having a preterm birth and for not breastfeeding (2,3); however, it is not known whether demographic disparities exist in the use of breast milk in neonatal intensive care units (NICUs). Data from CDC’s 2015 Maternity Practices in Infant Nutrition and Care (mPINC) survey, which does not collect patient-level demographics, were linked to the 2011–2015 U.S. Census Bureau’s American Community Survey (ACS)* to examine use of breast milk in NICUs based on demographic makeup of the hospital’s postal code area. Among U.S. hospitals with a NICU, the use of mother’s own milk and donor milk were examined by the percentage of non-Hispanic black (black) residents in the hospital postal code area, categorized as being above or below the national average (12.3%). In postal codes with >12.3% black residents, 48.9% of hospitals reported using mothers’ own milk in ≥75% of infants in the NICU, and 38.0% reported not using donor milk, compared with 63.8% and 29.6% of hospitals, respectively, in postal codes with ≤12.3% black residents. Further investigation is needed to understand variations in breast milk use in NICUs. Targeted efforts to increase breast milk use in hospitals located in postal codes where the percentage of black mothers is above the national average might help ensure more equitable access to breast milk for preterm and other high-risk infants.

The American Academy of Pediatrics (AAP) recommends that infants receive breast milk. In addition to the nutritional benefits of breast milk, consumption of breast milk by preterm infants is associated with lower rates of sepsis and necrotizing enterocolitis, and a number of other improved health outcomes (1). When mother’s own milk is contraindicated or insufficient, pasteurized donor milk is recommended (4). Black mothers are at increased risk for preterm birth and delivering a low birthweight infant and have lower rates of breastfeeding initiation and duration than do white and Hispanic mothers (2,3). Mothers of infants in the NICU often face challenges with breastfeeding because of their infants’ health conditions as well as being separated from their infants. The use of donor breast milk for high-risk infants is increasing, but access continues to be limited as hospital demand outpaces milk bank supply (4,5). Little is known about disparities in the use of breast milk for infants hospitalized in NICUs.

CDC’s mPINC survey is a census of facilities providing maternity care in the United States and territories (6). The survey is completed by the person or persons who are most knowledgeable about the facility’s practices related to infant nutrition. Information collected included facility characteristics, including hospital type; whether the facility is a teaching hospital; size (births per year); and neonatal care unit level (classified as level III or IV based on their ability to provide risk-appropriate subspecialty intensive care). Hospitals with a NICU report the approximate percentage of infants in the NICU routinely receiving mother’s own breast milk and banked donor breast milk. Because patient-level demographics are not collected as part of the mPINC, neighborhood-level data were obtained from the ACS to explore potential racial disparities. ACS is an ongoing survey of demographic, social, and housing characteristics, with postal code–level race data reported in 5-year estimates. Data from the 2015 mPINC were linked to 2011–2015 ACS data by hospital postal code. In 2015, the mPINC response rate was 82%, and included 2,582 participating facilities. Among 654 hospitals with a NICU, 602 (92.0%) had postal code–level race data available in ACS, including 576 (95.7%) and 568 (94.4%) that had data on mother’s own milk use and donor milk use, respectively. Hospitals were categorized as being in a postal code where the percentage of black residents was >12.3% (the national average) or ≤12.3%. No accepted cut-points exist for the prevalence of infants in the NICU receiving breast milk; therefore, receipt of breast milk was grouped into four categories at 25% intervals to illustrate the distribution of use across hospitals.

Because data were skewed, the median prevalence and interquartile range (IQR) of infants routinely receiving mother’s own and donor milk was calculated across hospitals, with stratification by the percentage of black residents in the hospital postal code above or below the national average. Chi-square, Fisher’s Exact, and, for continuous variables, Wilcoxon Rank-Sum tests were performed using statistical software.

Among 602 hospitals with NICUs, 222 (36.9%) were located in postal codes where the percentage of black residents exceeded the national average (Table 1). Overall, 145 of 580 (25.0%) hospitals were teaching hospitals, and 86 of 579 (14.9%) were government-run; in postal codes with higher percentages of black residents, the percentage of teaching hospitals (32.4%) and of government-run hospitals (20.5%) was higher than in postal codes with lower percentages of black residents (20.6% and 11.5%, respectively). NICU level and facility size were similar in hospitals in postal codes with high and low percentages of black residents.

Across all hospitals, the median estimated prevalence of infants in NICUs receiving mother’s own milk was 75.0% (IQR = 60.0%–86.0%); the percentage was higher in NICUs in postal codes with lower percentages of black residents (80.0%) than in those in postal codes with higher percentages of black residents (72.0%) (p<0.01) (Table 2). The median prevalence of infants receiving banked donor breast milk across all NICUs was 10.0% (IQR = 0%–20.0%); the percentage was higher in NICUs in postal codes with lower percentages of black residents (10.0%) than in NICUs in postal codes with higher percentages of black residents (5.0%) (p = 0.04) (Table 2).

Less than half (48.9%) of hospitals in postal codes with higher percentages of black residents reported that ≥75% of infants in the NICU received mother’s own breast milk, compared with 63.8% of NICUs in postal codes with lower percentages of black residents (Figure). Similarly, 38.0% of hospitals in postal codes with higher percentages of black residents reported that no infants in the NICU received donor breast milk, and 5.1% reported that at least half of infants in the NICU received donor breast milk, compared with 29.6% and 11.4%, respectively, of NICUs in postal codes with lower percentages of black residents (Figure).