title: Effect of maternal gestational weight gain on offspring DNA methylation: a follow-up to the ALSPAC cohort study.
abstract: BACKGROUND
  Several epidemiologic studies indicate that maternal gestational weight gain (GWG) influences health outcomes in offspring. Any underlying mechanisms have, however, not been established. A recent study of 88 children based on the Avon Longitudinal Study of Parents and Children (ALSPAC) cohort examined the methylation levels at 1,505 Cytosine-Guanine methylation (CpG) loci and found several to be significantly associated with maternal weight gain between weeks 0 and 18 of gestation. Since these results could not be replicated we wanted to examine associations between 0 and 18 week GWG and genome-wide methylation levels using the Infinium HumanMethylation450 BeadChip (450K) platform on a larger sample size, i.e. 729 newborns sampled from the Norwegian Mother and Child Cohort Study (MoBa).
  
  
  RESULTS
  We found no CpG loci associated with 0-18 week GWG after adjusting for the set of covariates used in the ALSPAC study (i.e. child's sex and maternal age) and for multiple testing (q > 0.9, both 1,505 and 473,731 tests). Hence, none of the CpG loci linked with the genes found significantly associated with 0-18 week GWG in the ALSPAC study were significant in our study.
  
  
  CONCLUSIONS
  The inconsistency in the results with the ALSPAC study with regards to the 0-18 week GWG model may arise for several reasons: sampling from different populations, dissimilar methylome coverage, sample size and/or false positive findings.
authors.affiliation: Division of Epidemiology, Norwegian Institute of Public Health, Marcus Thranes gate 6, P.O. Box 4404, 0403, Oslo, Norway. jon.bohlin@fhi.no.
authors.forename: Jon
authors.initials: J
authors.lastname: Bohlin
authors.affiliation: Division of Epidemiology, Norwegian Institute of Public Health, Marcus Thranes gate 6, P.O. Box 4404, 0403, Oslo, Norway. b.k.andreassen@medisin.uio.no.|Department of Molecular Biology, Institute of Clinical Medicine, University of Oslo, Oslo, Norway. b.k.andreassen@medisin.uio.no.
authors.forename: Bettina K
authors.initials: BK
authors.lastname: Andreassen
authors.affiliation: National Institute of Environmental Health Sciences, MD A3-05, PO Box 12233, Research Triangle Park, NC, 27709, USA. bonnie.joubert@nih.gov.
authors.forename: Bonnie R
authors.initials: BR
authors.lastname: Joubert
authors.affiliation: Division of Epidemiology, Norwegian Institute of Public Health, Marcus Thranes gate 6, P.O. Box 4404, 0403, Oslo, Norway. Maria.Christine.Magnus@fhi.no.
authors.forename: Maria C
authors.initials: MC
authors.lastname: Magnus
authors.affiliation: Public Health Sciences Division, Fred Hutchinson Cancer Research Center, Seattle, WA, 98109, USA. mcwu@fredhutch.org.
authors.forename: Michael C
authors.initials: MC
authors.lastname: Wu
authors.affiliation: Division of Epidemiology, Norwegian Institute of Public Health, Marcus Thranes gate 6, P.O. Box 4404, 0403, Oslo, Norway. Christine-Louise.Parr@fhi.no.
authors.forename: Christine L
authors.initials: CL
authors.lastname: Parr
authors.affiliation: Division of Epidemiology, Norwegian Institute of Public Health, Marcus Thranes gate 6, P.O. Box 4404, 0403, Oslo, Norway. SiriEldevik.Haberg@fhi.no.
authors.forename: Siri E
authors.initials: SE
authors.lastname: Håberg
authors.affiliation: Division of Epidemiology, Norwegian Institute of Public Health, Marcus Thranes gate 6, P.O. Box 4404, 0403, Oslo, Norway. Per.Magnus@fhi.no.
authors.forename: Per
authors.initials: P
authors.lastname: Magnus
authors.affiliation: National Institute of Environmental Health Sciences, MD A3-05, PO Box 12233, Research Triangle Park, NC, 27709, USA. sarah.reese@nih.gov.
authors.forename: Sarah E
authors.initials: SE
authors.lastname: Reese
authors.affiliation: Division of Epidemiology, Norwegian Institute of Public Health, Marcus Thranes gate 6, P.O. Box 4404, 0403, Oslo, Norway. Camilla.Stoltenberg@fhi.no.
authors.forename: Camilla
authors.initials: C
authors.lastname: Stoltenberg
authors.affiliation: National Institute of Environmental Health Sciences, MD A3-05, PO Box 12233, Research Triangle Park, NC, 27709, USA. london2@niehs.nih.gov.
authors.forename: Stephanie J
authors.initials: SJ
authors.lastname: London
authors.affiliation: Division of Epidemiology, Norwegian Institute of Public Health, Marcus Thranes gate 6, P.O. Box 4404, 0403, Oslo, Norway. Wenche.Nystad@fhi.no.
authors.forename: Wenche
authors.initials: W
authors.lastname: Nystad
mesh_terms: D000328:Adult; D001724:Birth Weight; D018899:CpG Islands; D019175:DNA Methylation; D044127:Epigenesis, Genetic; D005260:Female; D056426:Genetic Loci; D005865:Gestational Age; D006801:Humans; D007231:Infant, Newborn; D008137:Longitudinal Studies; D008297:Male; D009035:Mothers; D011247:Pregnancy; D015430:Weight Gain / Q000502:physiology*