[Neonatal hypernatraemic dehydration--why increasing incidence?]

Neonatal dehydration with hypernatraemia is a serious condition with risk of cerebral damage and death. Recent studies have reported a rising incidence.

A retrospective study was conducted at Hvidovre Hospital over a 5-year period to identify term or near-term infants (>35 weeks of gestation) who were admitted with a weight-loss >10%. Infants admitted between the 3rd and the 14th day of life with a discharge diagnosis code indicating dehydration were also included.

During the period a total of 89 infants were admitted and 24 had hypernatraemia. The incidence increased from 2.1 to 4.9 (RR 2,5-p >0.0008). All infants were breastfed and only 3 had had supplementation prior to admission. The weight-loss ranged between 270 and 1100 grams (equivalent to 10.1-29.7% reduction in birth weight) while lethargy and jaundice were frequent symptoms. Cerebral complications occurred for 8 infants and 2 developed permanent brain damage.

Breastfeeding should be encouraged but supplementation may be necessary for some infants. Infants born to primiparous women, infants heavy for gestational age and infants who do not thrive on day 4-5 appear to have a high risk. These infants could be identified by regular weighing and, if necessary, supplementation and follow-up should be instituted.