Breastfeeding-associated hypernatremia: Are we missing the diagnosis?

Objectives. To assess the incidence and complications of breastfeeding- associated hypernatremic dehydration among hospitalized neonates. Study Design. A retrospective study was conducted at Children's Hospital of Pittsburgh over a 5- year period, to identify otherwise healthy term and near- term (>= 35 weeks of gestation) breastfed neonates (< 29 days of age) who were admitted with serum sodium concentrations of > 150 mEq/ L and no explanation for hypernatremia other than inadequate milk intake. Results. The incidence of breastfeeding- associated hypernatremic dehydration among 3718 consecutive term and near- term hospitalized neonates was 1.9%, occurring for 70 infants. These infants were born primarily to primiparous women ( 87%) who were discharged within 48 hours after birth ( 90%). The most common presenting symptom was jaundice ( 81%). Sixty- three percent of infants underwent sepsis evaluations with lumbar puncture. No infants had bacteremia or meningitis. Infants had hypernatremia of moderate severity ( median: 153 mEq/ L; range: 150 - 177 mEq/ L), with a mean weight loss of 13.7%. Nonmetabolic complications occurred for 17% of infants, with the most common being apnea and/ or bradycardia. There were no deaths. Conclusion. Hypernatremic dehydration requiring hospitalization is common among breastfed neonates. Increased efforts are required to establish successful breastfeeding.