[Neonatal hypernatraemic dehydration--why increasing incidence?].

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

Materials and Methods: 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.

Results: 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.

Conclusions: 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.