The Type of Feeding at Discharge of Very Preterm Infants: Neonatal Intensive Care Units Policies and Practices Make a Difference.

Objective: To assess the influence of neonatal intensive care units (NICUs) on feeding practices at discharge of Portuguese very preterm infants. Materials and Methods: We analyzed data from 580 very preterm infants (<32 gestational weeks) discharged home from NICUs of two Portuguese regions and enrolled during 2011-2012 in Effective Perinatal Intensive Care in Europe population-based cohort. Maternal and infant characteristics were abstracted from medical records, and heads of NICUs provided the units characteristics. Feeding at discharge was classified as exclusive formula, exclusive breast milk or mixed, and differences among NICUs were obtained by comparison with pooled geometric mean odds of all NICUs, using multinomial logistic regression. Median odds ratios (MOR) were calculated to quantify variability among NICUs using multilevel logistic regression. Results: At discharge, 25.2% very preterm infants were exclusively on breast milk, 34.1% exclusively on formula, and 40.7% had mixed feeding, with a wide variation among NICUs. Exclusive breast milk increased in NICUs that had higher numbers of admissions, provided parents eating facilities, and by having designated members to support mothers who were breastfeeding. The individual NICU odds of mixed versus exclusive formula feeding ranged from 0.36 to 2.07 and for exclusive breast milk versus exclusive formula ranged from 0.16 and 5.11. Adjusting for individual and unit characteristics, heterogeneity across NICUs remained evident, being the MOR 1.33 for mixed feeding and 1.35 for exclusive breast milk. Conclusions: NICUs influence feeding practices independently of individual characteristics, highlighting the importance of institution-based interventions to promote breast milk.