Fig. 1.

Volvano plot of the association between placenta/cord blood DNA methylation and sPTB. a Volcano plot of the differentially methylated positions associated with sPTB in placenta. b Volcano plot of the differentially methylated positions associated with sPTB in cord blood. The x axis represents log2 transformed fold changes of DNA methylation level (M-values) between sPTB and term birth. The y axis represents log₂transformed p-values of the associations between each differentially methylated position and sPTB. The dashed horizontal lines represent p-value = 0.05, the solid horizontal lines represent Bonferroni corrected p-value = 0.05