Up-regulation of microRNA-202-3p in first trimester placenta of pregnancies destined to develop severe preeclampsia, a pilot study.

MicroRNA (miRNA) expression has not been studied during placentation in pregnancies that develop preeclampsia, when it likely manifests. In this pilot study, miRNA expression in late first trimester placenta from four pregnancies that developed severe preeclampsia matched to controls using the Affymetrix GeneChip® miRNA 3.0 Array identified 9 miRNAs differentially expressed, with miR-202-3p the most significantly overexpressed in severe preeclampsia. Real-time reverse transcription polymerase chain reaction (qRT-PCR) confirmed overexpression of miR-202-3p in a validation cohort, with a 7-fold increase in pregnancies that developed severe preeclampsia (p≤0.05). Differential miRNA expression, specifically miR-202-3p, is seen in first trimester placenta in severe preeclampsia.