Temporal changes in circulating miRNAs following gestational diabetes diagnosis: a pilot longitudinal study.

Currently, no clinical early predictive biomarkers of GDM exist. A key challenge is that many candidate biomarkers fluctuate during pregnancy. Previous studies with a single time point identified several miRNAs in early pregnancy associated with insulin sensitivity between 24 and 29 weeks of gestation, suggesting they serve as potential predictive biomarkers for GDM. However, the lack of longitudinal data limits our understanding of how these miRNAs behave over time. We conducted a longitudinal pilot study to evaluate the patterns of ten miRNAs, previously identified as potential early predictors of GDM. Blood samples were collected from 18 GDM women and 18 healthy pregnancies at 4 time points (GDM diagnosis, 28 weeks, 32 weeks, and one day before delivery). The levels of four placenta-specific C19MC miRNAs (miRNA-519d-5p, miRNA-512-3p, miRNA-516a-5p, and miRNA-517-5p) and six non-C19MC miRNAs (miRNA-141-3p, miRNA-143-3p, miRNA-218-5p, miRNA-221-3p, miRNA-483-5p, and miRNA-489-3p) were measured. The relative expressions of four C19MC miRNAs were significantly increased in GDM women at diagnosis, at 28 weeks of gestation, and one day before delivery. The relative expression of non-C19MC miRNA-221-3p was significantly decreased across all time points. The expression of non-C19MC miRNA-143-3p increased significantly at diagnosis and 28 weeks, and then declined before delivery. In contrast, the levels of non-C19MC miRNA-483-5p, miRNA-218-5p, and miRNA-489-3p were significantly decreased across all time points. No changes in miRNA-141-3p level were observed. Our pilot longitudinal study supports the predictive potential of C19MC miRNAs (miRNA-512-3p, miRNA-516a-5p, miRNA-517-5p) and non-C19MC miRNA-221-3p, which were previously identified as having elevated levels in early gestation.