Reference chart for relative weight change to detect hypernatraemic dehydration

Arch Dis Child. 2007 Jun;92(6):490-4. doi: 10.1136/adc.2006.104331. Epub 2006 Jul 31.

Abstract

Objective: The validity of the rule of thumb that infants may have a weight loss of 10% in the first days after birth is unknown. We assessed the validity of this and other rules to detect breast-fed infants with hypernatraemic dehydration.

Design: A reference chart for relative weight change was constructed by the LMS method. The reference group was obtained by a retrospective cohort study.

Participants: 1544 healthy, exclusively breast-fed infants with 3075 weight measurements born in the Netherlands and 83 cases of breast-fed infants with hypernatraemic dehydration obtained from literature.

Results: The rule of thumb had a sensitivity of 90.4%, a specificity of 98.3% and a positive predictive value of 3.7%. Referring infants if their weight change is below -2.5 SDS (0.6th centile) in the reference chart in the first week of life and using the rule of thumb in the second week had a sensitivity of 85.5%, a specificity of 99.4% and a positive predictive value of 9.2%.

Conclusions: The rule of thumb is likely to produce too many false positive results, assuming that for screening purposes the specificity needs to be high. A chart for relative weight change can be helpful to detect infants with hypernatraemic dehydration.

Publication types

  • Multicenter Study
  • Validation Study

MeSH terms

  • Breast Feeding
  • Dehydration / diagnosis*
  • Dehydration / epidemiology
  • Epidemiologic Methods
  • Evidence-Based Medicine
  • Female
  • Humans
  • Hypernatremia / diagnosis*
  • Hypernatremia / epidemiology
  • Infant Care / methods*
  • Infant, Newborn
  • Male
  • Netherlands / epidemiology
  • Reference Values
  • Referral and Consultation
  • Weight Loss*