Osmolality of carbohydrate solutions and gastric emptying in the newborn.

Gastric emptying in normal newborns was studied with use of a double marker technique. The volume of 200 to 400 mOsm carbohydrate solutions emptied from the stomach in 30 minutes was determined. To evaluate isocaloric solutions of different osmolalities, the osmolality of a 400-mOsm glucose solution was decreased to 300 and 200 mOsm/L by replacing a portion of the glucose with glucose oligosaccharides (GOSs). Because GOSs could be rapidly hydrolyzed in the duodenum, the effect of osmolality alone was studied by adding xylose to a 200-mOsm glucose solution to increase the osmolality to 300 and 400 mOsm/L. The volumes of the various solutions emptied in 30 minutes were not significantly different. These findings suggest that decreasing formula osmolality from 400 to 200 mOsm offers no intrinsic advantage with regard to gastric emptying.