In this study, on Pearson correlation analysis, among placental villi groups (normal first-, second- and third- trimester placenta and preeclampsia), revealed a significant positive and negative correlation between mRNA expression of DNMT1 vs. DNMT3A (r = 0.99; p < 0.001) and vs DNMT3B (r = −0.77), respectively. The gene discussed is DNMT3A; the disease is preeclampsia.