Oral feeding began when the infant was clinically stable in
terms of hemodynamics and had presented peristalsis according
to criteria established by the caretaker staff. Oral diet
progress depended on infant acceptance and was around
20 mL/kg/day.
In both groups, the change from orogastric tube to oral
feeding was initiated when the preterm infant reached the
gestational age of 34 weeks, regardless of weight, in compliance
with institutional routine and depending on an assessment
of its capacity to suck, swallow and breathe. A single,
external speech therapist, double-blinded for the study, performed
the clinical assessment of preterm infants' ability to
initiate oral feeding.
Control and experimental groups received the same guidance
regarding breast massage and pumping, financial support
for return to the hospital, readmission of mother for
breastfeeding and providing various breastfeeding guidelines
before and after discharge. In addition, every time mothers
from both groups were present at the neonatal ward, and
infant conditions allowed for it, it was requested that they
pump milk for direct administration. Mothers were given and
took advantage of opportunities to remain in the hospital
equally for both groups.
At discharge and at three and 6 months of corrected age,
preterm infants were classified as breastfed (exclusively or
not) and non-breastfed (using cups or bottles, no access to
breast). Physicians prescribed formula for the non-breastfed.
Analysis was made by intention to treat and by complete
cases9 and statistical significance was established at levels
below 5%. The difference between both groups was verified
through the following tests: Student's t test, Kruskal-Wallis
test, Mantel-Haenszel chi-square test or Fischer exact test.
The database was built in the EpiInfo environment, and all statistical
analyses were performed using SPSS statistical package
version 13