Tolerance of a standard intact protein formula versus a partially hydrolyzed formula in healthy, term infants.

Background: Parents who perceive common infant behaviors as formula intolerance-related often switch formulas without consulting a health professional. Up to one-half of formula-fed infants experience a formula change during the first six months of life.

Methods: The objective of this study was to assess discontinuance due to study physician-assessed formula intolerance in healthy, term infants. Infants (335) were randomized to receive either a standard intact cow milk protein formula (INTACT) or a partially hydrolyzed cow milk protein formula (PH) in a 60 day non-inferiority trial. Discontinuance due to study physician-assessed formula intolerance was the primary outcome. Secondary outcomes included number of infants who discontinued for any reason, including parent-assessed.

Results: Formula intolerance between groups (INTACT, 12.3% vs. PH, 13.7%) was similar for infants who completed the study or discontinued due to study physician-assessed formula intolerance. Overall study discontinuance based on parent- vs. study physician-assessed intolerance for all infants (14.4 vs.11.1%) was significantly different (P = 0.001).

Conclusion: This study demonstrated no difference in infant tolerance of intact vs. partially hydrolyzed cow milk protein formulas for healthy, term infants over a 60-day feeding trial, suggesting nonstandard partially hydrolyzed formulas are not necessary as a first-choice for healthy infants. Parents frequently perceived infant behavior as formula intolerance, paralleling previous reports of unnecessary formula changes.

Trial Registration: clinicaltrials.gov: NCT00666120.