title: Evaluation of DNA methylation status at differentially methylated regions in IVF-conceived newborn twins.
abstract: OBJECTIVE
  To examine the effect of assisted reproductive technology on the stability of DNA methylation at differentially methylated regions (DMRs) in twins conceived by IVF.
  
  
  METHODS
  Prospective clinical observational study.
  
  
  METHODS
  IVF center, university-affiliated teaching hospital.
  
  
  METHODS
  Fifty-nine pairs of twins were recruited, including 29 pairs conceived through IVF and 30 pairs of naturally conceived twins.
  
  
  METHODS
  Collection of umbilical cord blood samples.
  
  
  METHODS
  DNA was extracted from umbilical cord blood. Two maternally methylated regions (KvDMR1 and PEG1) and one paternally methylated region (H19/IGF2 DMR) were analyzed using bisulfite-based technologies.
  
  
  RESULTS
  Although H19/IGF2 DMR and KvDMR1 showed slightly more variable levels of methylation in IVF cases than in spontaneous cases, methylation indices did not reveal significant differences at three DMRs between IVF-conceived and naturally conceived twins.
  
  
  CONCLUSIONS
  Our results suggest no significant increase in imprint variability at these DMRs, but the greater variance in the IVF twins has a biologically meaningful consequence and may be a topic for future investigation. Large cohorts are needed to systematically assess the potential epigenetic risk in twins conceived with IVF.
authors.affiliation: Center of Reproductive Medicine, Women's Hospital, Department of Medical Genetics, School of Medicine, Zhejiang University, Hangzhou, Zhejiang, People's Republic of China.
authors.forename: Lei
authors.initials: L
authors.lastname: Li
authors.forename: Liya
authors.initials: L
authors.lastname: Wang
authors.forename: Fang
authors.initials: F
authors.lastname: Le
authors.forename: Xiaozhen
authors.initials: X
authors.lastname: Liu
authors.forename: Ping
authors.initials: P
authors.lastname: Yu
authors.forename: Jiangzhong
authors.initials: J
authors.lastname: Sheng
authors.forename: Hefeng
authors.initials: H
authors.lastname: Huang
authors.forename: Fan
authors.initials: F
authors.lastname: Jin
mesh_terms: D000328:Adult; D018899:CpG Islands / Q000235:genetics; D019175:DNA Methylation / Q000502:physiology*; D057890:Epigenomics; D005260:Female; D005306:Fertilization / Q000502:physiology; D005307:Fertilization in Vitro / Q000379:methods; D005865:Gestational Age; D006801:Humans; D007231:Infant, Newborn; D011247:Pregnancy; D014427:Twins / Q000235:genetics* / Q000378:metabolism; D014470:Umbilical Cord / Q000166:cytology / Q000378:metabolism; D055815:Young Adult