title: New and improved Israeli reference of birth weight, birth length, and head circumference by gestational age: a hospital-based study.
abstract: BACKGROUND
  Many centers in Israel still use pre-1970 reference data for neonatal weight, length and head circumference. A recently published population-based reference overestimated the weight of premature infants.
  
  
  OBJECTIVE
  To develop a national reference for birth weight, birth length and head circumference by gestational age for singleton infants in Israel.
  
  
  METHODS
  Data were collected on all singleton live births documented in the neonatal registry of Rabin Medical Center from 1991 to 2005 (n=82,066). Gestational age estimation was based on the last menstrual period until 1977 and early fetal ultrasound thereafter. Neonates with an implausible birth weight for gestational age (identified by the rule of median +/- 5 standard deviations or expert clinical opinion) were excluded. Reference tables for fetal growth by gestational age were created for males and females separately.
  
  
  RESULTS
  The growth references developed differed markedly from the Usher curves currently used in our department. Compared to the recently published population-based birth weight reference, our data were free of the problem of differential misclassification of birth weight for gestational age for the premature infants and very similar for the other gestational age groups. This finding reinforced the validity of our measurements of birth weight, as well as of birth length and head circumference.
  
  
  CONCLUSIONS
  Use of our new (birth length and head circumference) and improved (birth weight) gender-specific hospital-based reference for fetal growth may help to define normal and abnormal growth in the neonatal population of Israel and thereby improve neonatal care and public health comparisons.
authors.affiliation: Department of Neonatology, Rabin Medical Center (Beilinson Campus), Petah Tikva, Israel. shmueld@clalit.org.il
authors.forename: Shmuel
authors.initials: S
authors.lastname: Davidson
authors.forename: Nir
authors.initials: N
authors.lastname: Sokolover
authors.forename: Avi
authors.initials: A
authors.lastname: Erlich
authors.forename: Aviva
authors.initials: A
authors.lastname: Litwin
authors.forename: Nehama
authors.initials: N
authors.lastname: Linder
authors.forename: Lea
authors.initials: L
authors.lastname: Sirota
mesh_terms: D000465:Algorithms; D001724:Birth Weight / Q000502:physiology*; D001827:Body Height / Q000502:physiology*; D002508:Cephalometry; D002657:Child Development / Q000502:physiology*; D005260:Female; D005865:Gestational Age; D006257:Head / Q000033:anatomy & histology*; D006761:Hospitals / Q000706:statistics & numerical data*; D006801:Humans; D007231:Infant, Newborn; D008297:Male; D011247:Pregnancy; D012042:Registries / Q000706:statistics & numerical data*; D012189:Retrospective Studies