Neonatal hypernatremic dehydration due to excessively concentrated prepared milk formula.

Excessively concentrated milk formula was administered accidentally to five newborn infants. Diarrhea, dehydration, hypernatremia, and hyperosmolality were present in all of them. Abnormal neurologic manifestations during the acute disease were observed in one infant. On follow-up, psychomotor development and electroencephalographic recordings were normal in four infants. One infant, in whom accelerated growth of head circumference had been noted before the episode of diarrhea, was found to have obstruction of the foramen of Monro at the age of 6 weeks. Possible errors in preparing milk formulas by medical staffing resulting in hypertonic dehydration are stressed in this report.