Neonatal hypernatremic dehydration due to breast feeding was rarely reported in the French-language literature.
Case report: The authors report hypernatremic dehydration in a 10-day-old exclusively breast-fed infant. The course was favorable. Insufficient breast milk production has been reported for 30 years.
Conclusion: Early discharge from maternity units is frequent nowadays. Breast-fed newborns without a positive weight gain at discharge should be checked for their weight within the first ten days of life.