Effect of fortifying breast milk on gastric emptying.

A study was performed to determine if the addition of a fortifier to expressed breast milk (EBM) affected gastric emptying in low birthweight infants. Using ultrasonography, the gastric emptying of EBM alone was compared with that containing a fortifier, in a blind, crossover study. Twenty two low birthweight infants were studied: median (range) gestation 31.5 weeks (28-37); birthweight 1495 g (1000-2480 g). The gastric antral cross-sectional area (ACSA) was measured by ultrasonography before each feed and then sequentially after its completion until the ACSA returned to its pre-feed value. The half emptying time was calculated as the time taken for the ACSA to decrease to half the maximum increment. The mean difference (standard error) between half emptying times for EBM alone and for EBM with added fortifier was not significant: 1.48 (4.9) minutes. These data show that fortifying breast milk does not affect gastric emptying and suggests that the practice is unlikely to affect feed tolerance in low birthweight infants.