From Mother to Child: Epigenetic Signatures of Hyperglycemia and Obesity during Pregnancy.

BACKGROUND

In utero exposure to maternal hyperglycemia and obesity can trigger detrimental effects in the newborn through epigenetic programming. We aimed to assess the DNA methylation levels in the promoters of and genes from maternal blood, placenta, and buccal swab samples collected in children born to mothers with and without obesity and Gestational Diabetes Mellitus (GDM).

METHODS

A total of 101 Caucasian mother-infant pairs were included in this study. Sociodemographic characteristics, clinical parameters, physical activity, and adherence to the Mediterranean diet were evaluated in the third trimester of pregnancy. Clinical parameters of the newborns were recorded at birth.

RESULTS

A negative relationship between DNA methylation on the fetal side of the GDM placenta and birth weight (r = -0.630, = 0.011) of newborns was found. DNA methylation level was lower in newborns of GDM women (CpG1: 2.8% ± 3.0%, CpG2: 3.8% ± 3.3%) as compared to those of mothers without GDM (CpG1: 6.9% ± 6.2%, CpG2: 6.8% ± 5.6%; < 0.001 and = 0.0033, respectively), and it was negatively correlated with weight (r = -0.229; = 0.035), head circumference (r = -0.236; = 0.030), and length (r = -0.240; = 0.027) at birth. DNA methylation was higher on the fetal side of the placenta in obese patients as compared to normal-weight patients (66.0% ± 14.4% vs. 55.7% ± 15.2%, = 0.037), and it was associated with maternal total cholesterol (r = 0.770, = 0.015) and LDL-c (r = 0.783, = 0.012).

CONCLUSIONS

These results support the role of maternal and methylation in fetal programming and in the future metabolic health of children.