title: Secular trends in size at birth of Iranian neonates: meta-analyses of published and unpublished studies.
abstract: BACKGROUND
  Secular trend in birth sizes is a well-known indicator of living conditions of a society.
  
  
  OBJECTIVE
  This study conducted meta-analyses estimating the mean birth weight (BW) and birth length (BL) of Iranian neonates born between 1971 and 2010.
  
  
  METHODS
  Data were collected from published studies through literature searches using Pubmed, Google scholar, Irandoc, Iranmedex, SID, magiran and unpublished studies including theses and projects conducted at the three main Iranian medical universities between 1971-2010. Mean and SD of BW or BL with other relevant data were extracted from eligible studies.
  
  
  RESULTS
  Of 266 studies identified, 61 were found to be eligible. The combined BW was 3222 (95% CI = 3093-3351), 3233 (95% CI = 3203-3264) and 3152 grams (95% CI = 3114-3189) in the 1970s, 1990s and 2000s, respectively. The mean decrease of 81 grams in BW during the 2000s was significant compared to the 1990s. The combined BL in the 1970s, 1980s, 1990s and 2000s were 50.3 (95% CI = 49.2-51.4), 49.5 (95% CI = 46.6-52.3), 50.0 (95% CI = 49.7-50.3) and 50.2 cm (95% CI = 49.6-50.8), respectively. No significant changes in BL were observed.
  
  
  CONCLUSIONS
  This meta-analysis found a negative secular trend in BW of Iranian neonates during 2000s with a rate of ∼ 8.1 g/year.
authors.affiliation: Department of Clinical Nutrition and Dietetics, Faculty of Nutrition Sciences and Food Technology, National Nutrition and Food Technology Research Institute, Tehran, Iran.
authors.forename: Parvin
authors.initials: P
authors.lastname: Mirmiran
authors.forename: Nazanin
authors.initials: N
authors.lastname: Moslehi
authors.forename: Golaleh
authors.initials: G
authors.lastname: Asghari
authors.forename: Sara
authors.initials: S
authors.lastname: Jambarsang
authors.forename: Yadollah
authors.initials: Y
authors.lastname: Mehrabi
authors.forename: Fereidoun
authors.initials: F
authors.lastname: Azizi
mesh_terms: D001724:Birth Weight; D001827:Body Height; D001835:Body Weight; D005260:Female; D006801:Humans; D007231:Infant, Newborn; D007492:Iran; D008019:Life Style; D008297:Male