Effect on splanchnic oxygenation of breast milk, fortified breast milk, and formula milk in preterm infants.

Background: Enteral feeding induces mesenteric hemodynamic changes in preterm infants, which may vary according to the milk used. Our aim in this study was to evaluate changes of splanchnic regional oxygenation (rSOS) measured by near-infrared spectroscopy (NIRS) in infants fed with mother's own milk (MOM), fortified human milk (FHM), or preterm formula (PTF).

Methods: Infants born at 25-31 weeks of gestational age (n = 54) received a bolus of MOM, FHM, or PTF. rSOS and splanchnic fractional oxygen extraction ratio (FOES) were recorded 60 min before (T), and 30 min (T) and 120 min (T) after the beginning of bolus feeding.

Results: In the MOM group, rSOS and FOES did not change during the study period. In the FBM group, rSOS decreased from T to T and increased from T to T, while FOES changed in reverse. In the PTF group, rSOS decreased from T to T and from T to T, while FOES changed in reverse.

Conclusions: Splanchnic oxygenation was not affected by MOM feeding, was transiently decreased by FBM feeding, and was persistently decreased by PTF. These results suggest that preterm infants who received PTF has higher splanchnic tissue oxygen extraction compared to those who received MOM or FBM.

Impact: Human milk feeding is associated to a lower splanchnic energy expenditure than preterm formula feeding. Fortified human milk transiently increases splanchnic energy expenditure. Preterm formula should be used only in the absence of human milk.