Plumptre L, Tammen SA, Sohn KJ, et al. - Researchers assessed fetal DNA methylation and hydroxymethylation in correlation with maternal and cord blood levels of folate and unmetabolized folic acid, vitamin B-12, vitamin B-6, and choline, and evaluated potential modifying influences of 38 fetal genetic variants in 22 genes. In 368 pregnant women, measurements of nutrient blood levels were obtained in early pregnancy (12–16 wk of gestation) and at delivery (37–42 wk of gestation) and these levels were assessed in cord blood. Using LC-MS/MS, they quantified DNA methylation and hydroxymethylation in cord blood mononuclear cells. In a cohort of pregnant Canadian women, a link of maternal and cord blood folate levels with fetal DNA hydroxymethylation, but not with DNA methylation, was found. They also identified the possible link of high folate and low vitamin B-12 maternal status in early pregnancy, with reduced fetal DNA methylation and higher birth weight; this finding needs further exploration.