The role of maternal methylation in the association between prenatal meteorological conditions and neonatal H19/H19-DMR methylation.

Meteorological conditions during pregnancy can affect birth outcome, which has been linked to the H19 / H19 -differentially methylated region (DMR). However, the detailed mechanisms underlying this association are unclear. This was investigated in the present study to provide epidemiological evidence for elucidating the pathogenesis of adverse birth outcomes. A total of 550 mother-newborn pairs were recruited in Zhengzhou, China from January 2010 to January 2012. Meteorological data including temperature (T), relative humidity (RH), and sunshine duration (SSD) were obtained from the China Meteorological Data Sharing Service System. Bisulfite sequencing PCR was performed to determine the methylation levels of H19 / H19 -DMR using genomic DNA extracted from maternal peripheral and umbilical cord blood. The results showed that H19 -DMR methylation status in cord blood was positively associated with that in maternal blood. Neonatal H19 -DMR methylation was negatively associated with T and RH during the first trimester and positively associated with these variables during the third trimester. There was a positive correlation between neonatal H19 -DMR methylation and SSD during the second trimester and a negative correlation during the third trimester. Similar associations were observed between maternal H19 -DMR methylation and prenatal meteorological conditions. We also observed significant interaction effects of maternal H19 / H19 -DMR methylation and most prenatal meteorological factors on neonatal methylation, and found that changes in the methylation status of maternal H19 -DMR were responsible for the effects of prenatal meteorological conditions on neonatal methylation. In summary, neonatal H19 -DMR methylation was significantly associated with prenatal meteorological conditions, which was modified and mediated by maternal H19 -DMR methylation changes. These findings provide insights into the relationship between meteorological factors during pregnancy and adverse birth outcomes or disease susceptibility in offspring, and can serve as a reference for environmental policy-making. • Prenatal meteorological factors affect H19 -DMR methylation in mothers and newborns. • Weather changes in the 1st and 3rd trimester of pregnancy alter methylation status. • Methylation status in cord blood is positively related to that in maternal blood. • Maternal methylation modifies the effects of meteorology on neonatal methylation. [ABSTRACT FROM AUTHOR]