Breastfeeding Hypernatremic Dehydration: A Potentially Grave Threat to Breastfed Newborns
ABSTRACT: Breastfeeding hypernatremic dehydration (BFHD), although uncommon in a neonate, is a serious condition and a well-recognized cause of permanent neurologic abnormality or death if left untreated. It occurs in neonates who are fed exclusively on breast milk and results from a newborn’s inadequate intake or a mother’s inadequate production of breast milk. Newborns should be evaluated within 48 hours after discharge from the nursery, and BFHD should be suspected in any breastfed neonate who has significant weight loss and features of dehydration, which can be corrected by oral or intravenous fluid replacement.
A girl was born to a 25-year-old primigravida mother at 38 weeks of gestation via normal vaginal delivery with neither prenatal nor perinatal complications. At delivery, the neonate weighed 3,180 g. The newborn and mother were discharged home after 48 hours, at which time the girl weighed 2,950 g (having lost 7% of birth weight). She had been breastfed exclusively, apparently sucking well, taking alternate breasts at 3-hour intervals for 5 minutes at each time, without any other supplemental feedings.
At 6 days of life, during the first well-baby visit, the newborn was found to weigh 2,600 g, having lost 18% of her birth weight. The mother related that her daughter had produced 5 wet diapers each day, including one stool diaper.
On physical examination, the neonate was active and alert, with sunken anterior fontanels, moist mucous membranes, yellow discoloration of the skin, scleral icterus, and capillary refill of less than 2 seconds, with stable vital signs.
Initial laboratory studies revealed a hemoglobin concentration of 16 mg/dL and a hematocrit of 49%, with a leukocyte count of 7,200, and a normal differential count. Laboratory tests also disclosed the following values: sodium, 163 mEq/L; potassium, 3.5 mEq/L; chloride, 128 mEq/L; bicarbonate, 17 mEq/L; anion gap of 17 mEq/L; blood urea nitrogen, 55 mg/dL; and creatinine, 0.6 mg/dL. Urinalysis findings showed a specific gravity of 1.026, 2+ protein, 1+ ketones, with the remainder of the results normal.
The patient was given 1 bolus of normal saline at 20 mL/kg and was slowly rehydrated with 5% dextrose in 0.45% normal saline solution (40 mL/kg/d, including oral breastfeeding of 2 oz every 3 h totaling 140 mL/kg/d) over a period of 36 hours. She gained 520 g over 48 hours (Table).
Breastfeeding hypernatremic dehydration (BFHD), although uncommon in a neonate (1.9% incidence in term infants2), is a serious complication of inadequate intake and/or inadequate production and is a well-recognized cause of permanent neurologic abnormality or even death if left untreated.1 Sodium levels in breast milk vary, and highly elevated levels impair lactogenesis, creating a failure to breastfeed.3 The consequences of BFHD most commonly are neurologic dysfunction such as seizures, cerebral edema, and disseminated intravascular coagulation and subsequent secondary complications.
Compared with formula feeding, breastfeeding has been shown to be optimal for newborns. Generally owing to hospitals’ initiatives to encourage breastfeeding, the percentage of mothers who exclusively breastfeed their newborns is increasing. However, because of a lack of proper education of first-time mothers about how to breastfeed, the risk of hypernatremic dehydration in newborns has increased.
Hypernatremic dehydration in the neonatal period can cause permanent neurologic damage, because the brain is the organ that is most sensitive organ to changes in sodium concentration.3 Hypernatremia increases serum osmolality, driving fluid from cells and causing shrinkage of brain cells; this can result in tearing of bridging veins, causing brain hemorrhage.
Hypernatremic dehydration in a neonate could result from excessive sodium intake or from water deficit. Excess sodium intake in newborns could be a result of an infusion of sodium bicarbonate or the improper preparation of formula or oral rehydration solution. Many case reports have attributed BFHD to high sodium content in breast milk; it also can be attributed to low breast milk production in a mother.2
In our case, the mother continued to breastfeed while the newborn’s sodium levels came down, which suggested that her breast milk was not considerably high in sodium content.
BFHD has a strong association with primiparous mothers, which indicates the need for close observation of this population whose infants lose more than 10% of their birth weight.
The differential diagnosis includes diabetes insipidus as an important and rare cause of hypernatremic dehydration. It should be suspected in cases of hypernatremia along with low urine specific gravity and low urine osmolality, when vasopressin can be used to differentiate central and nephrogenic diabetes insipidus.
Most cases of BFHD are managed with intravenous fluid rehydration alone.4 In our case, however, after the initial bolus the patient was managed with intravenous and oral rehydration, which can be done in cases of mild dehydration. This approach can correct dehydration and provide an opportunity to improve breastfeeding techniques and increase weight gain, as in our case.
The potentially devastating consequences of BFHD can be prevented by educating mothers about breastfeeding techniques beginning in the prenatal period. We recommend mothers be seen within 2 days after discharge from the newborn nursery. Those with identifiable problems should be referred promptly for lactation management and supportive counseling. Additionally, newborns should be followed up closely within the first weeks after hospital discharge to check for weight gain and adequate hydration.
Naresh Reddivalla, MD, Nithi Fernandes, MD, Thais Queliz, MD, and Gerard Prosper, MD, are physicians in the Department of Pediatrics at Lincoln Medical and Mental Health Center in the Bronx, New York.
1. Moritz ML, Manole MD, Bogen DL, Ayus JC. Breastfeeding-associated hypernatremia: are we missing the diagnosis? Pediatrics. 2005;116(3):e343-e347.
2. Anand SK, Sandborg C, Robinson RG, Lieberman E. Neonatal hypernatremia associated with elevated sodium concentration of breast milk. J Pediatr. 1980;96(1):66-68.
3. van Amerongen RH, Moretta AC, Gaeta TJ. Severe hypernatremic dehydration and death in a breast-fed infant. Pediatr Emerg Care. 2001;17(3):175-180.
4. Zaki SA, Mondkar J, Shanbag P, Verma R. Hypernatremic dehydration due to lactation failure in an exclusively breastfed neonate. Saudi J Kidney Dis Transpl. 2012;23(1):125-128.