Factors Influencing Breast Milk versus Formula Feeding at Discharge for Very Low Birth Weight Infants in California

Objective

To investigate incidence and factors influencing breast milk feeding at discharge for very low birth weight infants (VLBW) in a population-based cohort.

Study design

We used data from the California Perinatal Quality Care Collaborative to calculate incidence of breast milk feeding at hospital discharge for 6790 VLBW infants born in 2005–2006. Multivariable logistic regression was used to examine which sociodemographic and medical factors were associated with breast milk feeding. The impact of removing risk adjustment for race was examined.

Results

At initial hospital discharge, 61.1% of VLBW infants were fed breast milk or breast milk supplemented with formula. Breast milk feeding was more common with higher birth weight and gestational age. After risk adjustment, multiple birth was associated with higher breast milk feeding. Factors associated with exclusive formula feeding were Hispanic ethnicity, African American race, and no prenatal care. Hospital risk-adjusted rates of breast milk feeding varied widely (range 19.7% to 100%) and differed when race was removed from adjustment.

Conclusions

A substantial number of VLBW infants were not fed breast milk at discharge. Specific groups may benefit from targeted interventions to promote breast milk feeding. There may be benefit to reporting risk-adjusted rates both including and excluding race in adjustment when considering quality improvement initiatives.

CCS, California Children's Services, CPQCC, California Perinatal Quality Care Collaborative, IVH, Intraventricular hemorrhage, NICU, Neonatal intensive care unit, VLBW, Very low birth weight