The associations among maternal gestational weight gain, cord blood DNA methylation, and offspring childhood high BMI

ObjectiveThe objective of this study was to explore the associations among maternal gestational weight gain (GWG), cord blood DNA methylation, and high BMI.MethodsUsing the Illumina Infinium MethylationEPIC Bead Chip, GWG-related methylation sites were screened in 40 cord blood samples using a cohort design, and the association of these sites with children's BMI status at 3 years was examined. Sites simultaneously related to GWG and children's BMI were validated in an external dataset. The mediation effect of target differential methylation probes in the association between GWG and children's BMI was also explored.ResultsWe identified 66 GWG-related differential methylation probes in cord blood, and four sites, including cg09973771 (SNTG2), cg00254258 (PRDM16), cg02672830 (MCPH1), and cg15424377, were found to be associated with children's BMI at age 3 years. The mediating effect of cord blood DNA methylation was not detected in the association between GWG and children's high BMI status. Out of the four sites screened, methylation level of site cg09973771 (SNTG2) in peripheral blood showed nominal significant differences among children with different BMI statuses at age 3 years.ConclusionsMaternal GWG and childhood BMI status at age 3 years were associated with newborn cord blood DNA methylation.