Can microRNA profiling in maternal blood identify women at risk for preterm birth?

OBJECTIVE: MicroRNAs (miRNAs), which are highly conserved single-stranded noncoding RNAs that play a crucial role in gene regulation, have now been identified as important players in many diseases states. MiRNAs have also been demonstrated to be reliable and useful biomarkers to identify those women who are at risk for specific adverse outcomes. The objective of this study was to determine whether miRNA profiles in maternal blood are different in women who are destined to have a preterm, compared with a term, birth. STUDY DESIGN: A nested case-control study was performed with maternal serum that was collected as part of a larger prospective cohort. MiRNA expression profiles in maternal serum were compared between women who ultimately had a preterm birth (n = 40) compared with term birth (n = 40). MiRNA expression profiles were created with the use of the Affymetrix GeneChip miRNA Array. The data were analyzed with the significance of analysis of microarrays and principle components analyses. A false discovery rate of 20% was used to determine the most differentially expressed miRNAs. RESULTS: Of the 5640 miRNAs that were analyzed on the array, 4 miRNAs were significantly different between cases and control subjects. Two of the 4 miRNAs were mature miRNAs. The fold difference in expression was <2 for all 4 miRNAs. CONCLUSION: MiRNA profiles in maternal blood were not significantly different in women who were destined to have a preterm, compared with a term, birth. MiRNAs in maternal blood are unlikely to become clinically useful biomarkers for the prediction of preterm birth.