Genome-wide temporal landscaping of DNA methylation in pregnant women delivering at term: a GARBH-InI study.

Background: We performed an epigenome-wide longitudinal DNA methylation study on an Indian cohort of pregnant women, GARBH-Ini, at three time points during pregnancy and at delivery. Aim & objective: Our aim was to identify temporal DNA methylation changes in maternal peripheral blood during the period of gestation and assess their impact on biological pathways critical for term delivery. Results: Significantly differentially methylated CpGs were identified by linear mixed model analysis (Bonferroni p < 0.01) and classified into two distinct temporal methylation trends: increasing and decreasing during gestation. Genes with upward methylation trend were enriched for T-cell activity, while those with a downward trend were enriched for solute transport and cell structure organization functions. Conclusion: Consistent trends of DNA methylation in maternal peripheral blood point to the sentinel function of T cells in the maintenance of pregnancy, and the importance of coordinated cellular remodeling to facilitate term delivery.