[Severe hyperosmolarity caused by dietary error in the newborn. A disorder of particular concern in migrants]

Hyperosmolarity as a result of dietary error is a fairly common condition. It is more grave than "thirst fever", the benign reputation of which should not be taken too lightly. The consequences may be serious: death or sequelae related to vascular thrombosis or cerebral lesions. Prevention should be possible in most instances as long as obstetricians, paediatricians, midwives and nursery nurses are aware of the danger of overconcentrated milk formula. Its treatment remains fraught with hazard.