Villous placental genomic DNA from 10 obese (BMI 34.0±2.9) and 10 healthy BMI (23.4±2.3) women with uncomplicated pregnancy was collected. Methylated and hydroxymethylated DNA immunoprecipitation-chip was performed on the NimbleGen 2.1M high-density DNA methyl-ation array. Differentially methylated/hydroxymethylated genes were identified between groups, differences confirmed by pyrosequencing and gene expression measured by qRT-PCR. Results: Increased numbers of methylated (14,233 vs 12,319) and decreased numbers of hydroxymethylated regions (9,797 vs 11,789) were seen across the genome in obese vs healthy groups. Pathway analysis showed hyper-meth-ylated genes in obese pregnancies that are involved in defense response, cell adhesion, female pregnancy and lipid digestion. In parallel hypo-hydrox-ymethylated genes in obese pregnancies revealed functional enrichments for hormone secretion, defense/inflammatory response, TNF production and insulin secretion. Specifically the placental lactogen-growth hormone (CSH/ GH) and pregnancy-specific glycoprotein (PSG) gene clusters were differen-tially methylated/hydroxymethylated and mRNA expression decreased with obesity. Pyrosequencing of CMTM1 gene confirmed methylation array data. Conclusions: We find differential methylation/hydroxymethylation occurs in the placenta with increasing maternal BMI. As the balance of 5mC and 5hmC affects gene expression, this may be a mechanism whereby maternal adiposity affects placental gene expression and function, and develop-mental programming in an epigenetic manner. The low efficiency of nuclear reprogramming of the donor cells effects the epigenetic regulation bovine cloned embryos. The high incidence of fetal malformation and several placental abnormalities in cloned pregnancy suggests that this epigenetic deregulation is not only important for preg-nancy establishment but also for proper placenta formation in the cow. Furthermore, human placenta shows high variable global DNA-methyl-ation suggesting that some placental cells have more plasticity on their gene expression to mediate materno-fetal communication. Objective: Investigate the pattern of global DNA-methylation (5mC) and DNA-hydroximethylation (5hmC) in bovine cloned placentomes. Methods: Control and cloned placentomes from first (n¼5) and third (n¼6) trimester of pregnancy were processed for IHC analysis using anti-5mC or -5hmC antibodies. Results: Trophoblast cells showed low or no staining for 5mC (DNA-methylation) whereas, maternal showed high levels of 5mC. Trophoblast giant cells (TGCs) were fainted stained for 5mC. In control placenta, the ratio of maternal:fetal of 5mC was higher in first trimester and decrease in third trimester. However in cloned placentomes this ratio was constant throughout pregnancy being to control placentas in third trimester. There was no difference of 5hmC staining in both control and cloned pregnancy and no difference was found between maternal and fetal tissues. The most difference was the high staining of trophoblast giant cells for 5hmC. Conclusion: Cloned placentomes have a pattern of DNA global epigenetic modifications similar to control in third trimester, probably due the defi-ciency in demethylation process during embryo development. Financial support: CAPES