National Trends in the Provision of Human Milk at Hospital Discharge Among Very Low-Birth-Weight Infants

Abstract

Human milk confers important health benefits to very low-birth-weight (VLBW) infants (≤1500 g). The extent to which the use of human milk has changed over time and the factors associated with human milk use nationally in this population are poorly understood. To describe US trends in the provision of human milk at hospital discharge for VLBW infants during the past decade according to census region and maternal race/ethnicity, quantify associations of census region and maternal race/ethnicity with the provision of human milk at hospital discharge, and examine regional and state variations in any provision of human milk at hospital discharge among racial/ethnic groups. A cohort study was conducted of 346 248 infants, born at 23 to 29 weeks' gestation or with a birth weight of 401 to 1500 g, who were cared for at 802 US hospitals in the Vermont Oxford Network from January 1, 2008, to December 31, 2017. The US census region was categorized as West, Midwest, Northeast, and South (reference). Maternal race/ethnicity was categorized as non-Hispanic white (reference), non-Hispanic black, Hispanic, Asian and Pacific Islanders, and Native American. Any provision of human milk at hospital discharge, defined as the use of human milk as the only enteral feeding or the use of human milk in combination with fortifier or formula. Of the 346 248 infants in the study (172 538 boys and 173 710 girls), 46.2% were non-Hispanic white, 30.1% were non-Hispanic black, 18.3% were Hispanic of any race, 4.7% were Asian and Pacific Islanders, and 0.8% were Native American. Any provision of human milk at hospital discharge increased steadily among all infants, from 44% in 2008 to 52% in 2017. There were increases across all US census regions and racial/ethnic groups. Any provision of human milk at hospital discharge was higher in the West (among singleton births: adjusted prevalence ratio, 1.32; 95% CI, 1.25-1.39; among multiple births: adjusted prevalence ratio, 1.28; 95% CI, 1.21-1.35) and Northeast (among singleton births: adjusted prevalence ratio, 1.11; 95% CI, 1.04-1.19; among multiple births: adjusted prevalence ratio, 1.11; 95% CI, 1.04-1.19), compared with the South, and was higher among Asian mothers (among singleton births: adjusted prevalence ratio, 1.21; 95% CI, 1.18-1.25; among multiple births: adjusted prevalence ratio, 1.12; 95% CI, 1.09-1.15) and lower among Hispanic (among singleton births: adjusted prevalence ratio, 0.98; 95% CI, 0.96-1.01; among multiple births: adjusted prevalence ratio, 0.88; 95% CI, 0.86-0.91), Native American (among singleton births: adjusted prevalence ratio, 0.64; 95% CI, 0.59-0.70; among multiple births: adjusted prevalence ratio, 0.59; 95% CI, 0.50-0.69), and non-Hispanic black mothers (among singleton births: adjusted prevalence ratio, 0.67; 95% CI, 0.65-0.70; among multiple births: adjusted prevalence ratio, 0.57; 95% CI, 0.54-0.60), compared with non-Hispanic white mothers. These results were robust to adjustment for birth year and infant characteristics. Wide regional and state variations were found in any provision of human milk at hospital discharge. Overall prevalence of any provision of human milk at hospital discharge among VLBW infants has steadily increased during the past decade. Disparities by US region and race/ethnicity in the provision of human milk exist and have not diminished over time.