DNA methylation profiles of plasma DNA between pregnant and non-pregnant women were compared at three levels.

<p>There are (A) overall, (B) individual CpG sites, and (C) DNA methylation patterns. Grey and white boxes in the boxplot represent the pregnant and non-pregnant groups, respectively. P and N represents the group of pregnant and non-pregnant women, respectively. 0 and 1 represent unmethylated and methylated status for CpG sites, respectively.