Epigenome-wide meta-analysis of blood DNA methylation in newborns and children identifies numerous loci related to gestational age

Preterm birth and shorter duration of pregnancy are associated with increased morbidity in neonatal and later life. The epigenome is known to have an important role during fetal development. The best studied epigenetic modification is DNA methylation. We performed meta-analysis of Illumina’s HumanMethylation450-array associations between gestational age and cord blood DNA methylation in 3,648 newborns from 17 cohorts without common pregnancy complications, induced delivery or Caesarean section from the Pregnancy And Childhood Epigenetics (PACE) Consortium. We identified 8,899 CpGs annotated to 4,966 genes in cord blood that were associated with gestational age (range 27-42 weeks), at Bonferroni significance, P < 1.06×10⁻⁷, of which 3,343 were novel.