title: First-day weight loss predicts eventual weight nadir for breastfeeding newborns.
abstract: OBJECTIVE
  To examine the relationship between high (≥5%) weight loss during the first 24 h after birth and eventual excess weight loss (EWL) of ≥10% of birth weight.
  
  
  METHODS
  Retrospective cohort study.
  
  
  METHODS
  Kaiser Permanente Northern California hospitals.
  
  
  METHODS
  63 096 infants born at ≥36 weeks in 2009-2010, of whom 59 761 (94.5%) had a weight subsequent to birth weight measured at <24 h.
  Per cent of birth weight lost by 24 h of age.
  
  
  METHODS
  Weight nadir, defined as the lowest recorded inpatient or outpatient weight in the first 30 days after birth, expressed as a percentage of birth weight.
  
  
  RESULTS
  Among infants who breastfed at least once, mean (±SD) weight nadir was 6.3±3.5% below birth weight, and 9.6% of the newborns lost ≥10% of birth weight. Among 2670 infants who lost ≥5% of their birth weight in the first 24 h, 782 (29%) eventually developed EWL, compared with 4840 (8%) of 57 109 infants who lost <5% (p<0.0005). In multivariate analysis, ≥5% first-day weight loss predicted eventual EWL (≥10%) with an OR of 4.06 (95% CI 3.69 to 4.46) after adjusting for gestational age, method of delivery, maternal race/ethnicity and hospital of birth.
  
  
  CONCLUSIONS
  High first-day weight loss predicts eventual weight nadir and can be used to identify infants who might benefit from targeted interventions to support breastfeeding and prevent EWL.
authors.affiliation: Department of Pediatrics, School of Medicine, University of California, , San Francisco, California, USA.
authors.forename: Valerie J
authors.initials: VJ
authors.lastname: Flaherman
authors.forename: Michael W
authors.initials: MW
authors.lastname: Kuzniewicz
authors.forename: Sherian
authors.initials: S
authors.lastname: Li
authors.forename: Eileen
authors.initials: E
authors.lastname: Walsh
authors.forename: Charles E
authors.initials: CE
authors.lastname: McCulloch
authors.forename: Thomas B
authors.initials: TB
authors.lastname: Newman
mesh_terms: D001724:Birth Weight / Q000502:physiology*; D001835:Body Weight; D001942:Breast Feeding; D002140:California; D015331:Cohort Studies; D006801:Humans; D007227:Infant Nutritional Physiological Phenomena / Q000502:physiology*; D007231:Infant, Newborn; D015999:Multivariate Analysis; D011237:Predictive Value of Tests; D012189:Retrospective Studies; D013997:Time Factors; D015431:Weight Loss / Q000502:physiology*
keywords: General Paediatrics; Growth; Health services research; Nutrition