Moderate hypernatremic dehydration in newborn infants: retrospective evaluation of 64 cases

This study was carried out to assess the incidence, presenting complaints, risk factors, and methods for prevention of hypernatremic dehydration among term and near-term breastfeeding infants.

We retrospectively evaluated term and near-term (> or =35 weeks of gestation) neonates admitted to our neonatology department, during a four-year period with serum sodium concentrations of > or =146 mEq/L. A detailed maternal and infant history and examination including presenting complaints, risk factors, feeding problems, and weight loss, if present, were registered.

Among 1150 neonates admitted to our unit, 64 (5.6%) had serum sodium concentrations of >145 mEq/L, in whom 43 of them had sodium concentrations of >149 mEq/L. The most common presenting complaint was jaundice in 30 patients (48%). Forty-one (95%) of the 43 patients described a more than 7% weight loss and there was a positive correlation between serum sodium and urea and creatinine concentrations, and a negative correlation between serum sodium and glucose concentrations in these patients (p < 0.05). There was no difference between patients with sodium >149 mEq/L and <149 mEq/L with respect to maternal age, parity, educational level, hospital stay, type of delivery, and anesthesia and also with respect to seasons (p > 0.05).

Weight loss in an infant of greater than 7% from birth weight increases the risk of hypernatremia, a weight loss limit that is lower than the previously reported 10%. This indicates possible breastfeeding problems and requires more intensive evaluation of breastfeeding and possible interventions to correct problems and improve milk production and transfer.