INTRODUCTION:
Late preterm and early term infants represent a substantial proportion of live births and constitute a vulnerable neonatal population due to physiological immaturity, increased morbidity, and a higher likelihood of rehospitalization. Breastfeeding is recognized as one of the most impactful public health interventions, contributing to reduced infant mortality, improved neurodevelopment, and benefits throughout the life course. In Brazil, the Unified Health System, through public policies such as the Baby-Friendly Hospital Initiative and Kangaroo Mother Care, plays a fundamental role in promoting, protecting, and supporting breastfeeding, ensuring universal access to maternal and neonatal care.

METHODS:
This cross-sectional, descriptive, retrospective study analyzed medical records of newborns admitted to the rooming-in unit of a public teaching hospital in the state of Espírito Santo, Brazil, between March 2021 and October 2022. Variables assessed included gestational age, length of hospital stay, in-hospital weight loss, and type of feeding at hospital discharge.

RESULTS:
A total of 1,139 newborns were evaluated, of whom 13.96% were late preterm and 50.4% were early term infants. These groups experienced longer hospital stays and greater weight loss compared to full-term newborns. Breastfeeding at hospital discharge was observed in 81.76% of late preterm infants and 86.34% of early term infants, with an overall exclusive breastfeeding prevalence of 77.6%. Exclusive formula feeding at discharge occurred only among newborns with documented clinical contraindications to breastfeeding.

CONCLUSIONS:
The findings indicate that public policies implemented within Brazil’s public health system are effective in strengthening breastfeeding at hospital discharge, even among vulnerable neonatal populations. Reinforcing these strategies is essential to reduce neonatal morbidity and mortality, improve health outcomes, and promote equity in maternal and child health.