MicroRNA profiling in umbilical cord plasma: links to maternal metabolism and neonatal metabolic and inflammatory traits.

MicroRNAs (miRNAs) are regulators of mRNA translation and play crucial roles in various physiological and pathological processes. In this study, we profiled miRNAs in umbilical cord plasma (UCP) to explore the association of neonatal circulating miRNAs with maternal metabolic parameters and neonatal anthropometric, metabolic and inflammatory characteristics in healthy pregnancies. Data and UCP samples were collected from 16 pregnancies, equally divided between normal-weight and overweight mothers and between male and female newborns. Using next-generation sequencing, we identified and quantified miRNAs in UCP, alongside the analysis of metabolic and inflammatory parameters. Our results revealed that the majority of UCP miRNAs are sensitive to maternal and neonatal characteristics, particularly maternal body mass index, gestational weight gain, placental weight, UCP leptin, UCP C-reactive protein and UCP insulin levels. Notably, we identified a strong association between the placenta-derived chromosome 19 microRNA cluster (C19MC) and placental weight, gestational weight gain, UCP insulin and neonatal weight. Likewise, the pregnancy-specific chromosome 14 microRNA cluster (C14MC) was associated with maternal body mass index and UCP leptin. Our study highlights the sensitivity of UCP miRNAs to maternal metabolic conditions, demonstrates their association with neonatal metabolic and inflammatory traits, and underscores the potential role of circulating cord blood miRNAs in fetal metabolism and development. KEY POINTS: MicroRNAs (miRNAs) are regulatory RNA molecules that modulate protein expression. They are present in all body fluids and umbilical cord plasma and are affected by metabolic changes. Pregnancy is a state of metabolic change in the mother, and maternal metabolism affects fetal development. We found that the composition of umbilical cord blood miRNAs is associated with maternal and neonatal metabolism. Pregnancy-specific groups of miRNAs showed particular patterns, with miRNAs encoded by a region of chromosome 14 associated with maternal body mass index and with miRNAs encoded by a specific region of chromosome 19 associated with umbilical cord plasma insulin. MicroRNAs represent a separate dimension through which maternal metabolism can influence fetal development.