title: Epigenetic dysregulation of Insulin-like growth factor (IGF)-related genes and adverse pregnancy outcomes: a systematic review.
abstract: OBJECTIVE
  Preterm birth (PTB), low birth weight (LBW) and small for gestational age (SGA) are leading causes of neonatal mortality and morbidity around the world. Epigenetic alterations of the human genome may be involved in the causal chain of adverse pregnancy outcomes. In this systematic review we investigated whether PTB, LBW and SGA are associated with epigenetic dysregulation of insulin-like growth factor-related genes (IGF).
  
  
  METHODS
  We searched MEDLINE and EMBASE for peer-reviewed articles about IGF and PTB, LBW and SGA published up to February 2015. Two independent reviewers selected original, controlled, human studies published in any language and graded them using the Newcastle-Ottawa Quality Assessment Scale. Disagreements were resolved by consensus with a third reviewer.
  
  
  RESULTS
  Eighteen observational studies of low-to-moderate quality met the eligibility criteria out of 210 unique studies. There was substantial heterogeneity across studies. Most studies reported no, limited or borderline association between epigenetic changes (methylation or imprinting) of IGF-related genes and LBW or SGA. There were no IGF-related epigenetic studies of PTB.
  
  
  CONCLUSIONS
  Overall, evidence of an association between epigenetic abnormalities of IGF-related genes and LBW or SGA was weak and inconsistent. Methodological concerns limited results validity.
authors.affiliation: a Department of Health Promotion , Social and Behavioral Health, College of Public Health, University of Nebraska Medical Center , Omaha , NE , USA .
authors.forename: Drissa M
authors.initials: DM
authors.lastname: Toure
authors.affiliation: b Department of Epidemiology , College of Public Health, University of Nebraska Medical Center , Omaha , NE , USA .
authors.forename: Lorena
authors.initials: L
authors.lastname: Baccaglini
authors.affiliation: c Department of Health Policy and Management , Jiann-Ping Hsu College of Public Health, Georgia Southern University , Statesboro , GA , USA .
authors.forename: Samuel T
authors.initials: ST
authors.lastname: Opoku
authors.affiliation: b Department of Epidemiology , College of Public Health, University of Nebraska Medical Center , Omaha , NE , USA .
authors.forename: Debora
authors.initials: D
authors.lastname: Barnes-Josiah
authors.affiliation: d McGoogan Library of Medicine, University of Nebraska Medical Center , Omaha , NE , USA , and.
authors.forename: Roxanne
authors.initials: R
authors.lastname: Cox
authors.affiliation: d McGoogan Library of Medicine, University of Nebraska Medical Center , Omaha , NE , USA , and.
authors.forename: Teresa
authors.initials: T
authors.lastname: Hartman
authors.affiliation: e Department of Biochemistry and Molecular Biology , University of Nebraska Epigenomics Core Facility , Omaha , NE , USA.
authors.forename: David
authors.initials: D
authors.lastname: Klinkebiel
mesh_terms: D044127:Epigenesis, Genetic; D057890:Epigenomics; D005260:Female; D006801:Humans; D007230:Infant, Low Birth Weight; D007236:Infant, Small for Gestational Age; D008297:Male; D064887:Observational Studies as Topic; D011247:Pregnancy; D047928:Premature Birth / Q000235:genetics*; D017526:Receptor, IGF Type 1 / Q000235:genetics*; D017527:Receptor, IGF Type 2 / Q000235:genetics*
chemical_list: D017527:Receptor, IGF Type 2; D017526:Receptor, IGF Type 1
keywords: Birth weight; epigenetics; gestational age; insulin-like growth factors; preterm birth