Our patient is a 3180g female born to a 25 year-old primigravida at 38 weeks by normal delivery with no complications. The baby was discharged home after 48 hours weighing 2950 grams (lost 7 % of birth weight), exclusively breast-fed, apparently sucking well, at 3 hour intervals, without other supplemental feedings. At 6 days, she weighed 2,600 grams (Lost 18 % of birth weight). She produced 5 wet diapers each day including one stool. On exam, she was active, alert with sunken anterior fontanels, moist mucous membranes, yellow discoloration of skin and sclera, and well-perfused with stable vitals. Initial laboratory studies revealed hemoglobin 16mg/dL and hematocrit 49mg/dL, with leukocyte count 7200, normal differential, sodium 163mmol/L, potassium 3.5mmol/L, chloride 128mmol/L, bicarbonate 17mmol/L, BUN/Creatinine 55/0.6mg/dL, Urinalysis showed specific gravity 1.026, 2+ protein, 1+ ketones and rest normal. She was given 1 bolus of normal saline and slowly rehydrated with 5% dextrose in 0.45 normal saline solution (40 ml/kg/day including breast-feeding totaling 140 ml/kg/day) over a period of 36 hrs. She gained 520 grams over 48 hours when she was discharged with serum sodium 146mg/dL.
Breast-feeding has been shown to be optimal for newborns. However, breast-feeding hypernatremic dehydration (BFHD) is a rare complication of inadequate intake and/or inadequate production. Due to inadequate breast-feeding education for primiparous mothers, there is an increased risk of hypernatremic dehydration in newborns. It is uncommon but a serious and well-recognized cause of permanent neurologic abnormality because of the brain’s sensitivty for sodium changes. Hypernatremia will increase the serum osmolality by driving fluid out of cells, causing shrinkage resulting in tearing of bridging veins, and brain hemorrhage.
Hypernatremic dehydration could be a result excessive sodium intake or water deficit in excess of sodium. Excess sodium intake in newborns could be because of improper preparation of formula, oral rehydration solution, or high sodium content in breast milk. In our case, the mother continued to breast-feed while the levels came down which showed that her breast-milk was not considerably high in sodium content.
Most cases of hypernatremic dehydration due to inadequate breast feeding are managed with intravenous fluid rehydration alone, but in cases of mild dehydration, as was our case, can also be managed both intravenous and oral rehydration. This can correct dehydration as well as give an opportunity to improve techniques of breast-feeding and increase weight gain.
BFHD has a strong association with primiparous mothers which warrants increased antenatal education and surveillance of their infants who lose more than 10% of their birth weight. Additionally, we recommend newborns be seen promptly after discharge from the nursery, particuarly those with identifiable problems to assess weight gain and adequate hydration and to avoid the devastating consequences of hypernatremic dehydration.