Figure 3.

Persistence across the gestational period. (A) Distribution of predicted gestational age (via predictAge() function from the planet R package) in full term and individual trimester datasets (B) The persistence correlation analysis shows plots of DNA methylation differences for the three trimesters. The green colored points are the CpG sites that were conserved across gestation. The blue colored points represent the CpG sites that were considered significant for each trimester. The correlation values between the trimester and the full term analysis increase as the full term is approached. (C) Persistence of hits discovered from the full term placentas throughout gestation. If the significant site from the full term had a p value less than 0.05 and had the same direction of association in the preterm analysis, then it was considered “persistent.” For example, of the 5,209 differentially methylated sites identified in the full term sample that passed QC in all three individual early term samples, 194 CpG sites were persistent per this definition across all three trimesters. (D) Comparison of female and male fetuses’ methylation values at different points during gestation. cg17612569 was consistently significant at all time points.