Towards early diagnosis of Preeclampsia: Emerging roles of circulating microRNAs.

Preeclampsia (PE) is a pregnancy-specific hypertensive disorder and a major contributor to maternal and fetal morbidity and mortality worldwide. Its pathophysiology involves placental dysfunction, immune dysregulation, heightened inflammatory activation, imbalance between angiogenic and antiangiogenic factors, and metabolic alterations. Despite extensive research, early diagnosis of PE remains challenging, as current approaches rely on specialized professionals, costly biochemical tests, and advanced equipment, which are not always widely accessible. Emerging evidence indicates that microRNAs (miRNAs) secreted by placental trophoblasts play a central role in regulating placental function, and their altered expression is closely associated with both early- and late-onset PE. Circulating miRNAs in maternal blood therefore represent promising early biomarkers of this gestational complication. However, the heterogeneity of miRNA expression across populations, shaped by genetic, epigenetic, and ethnic factors, highlights the need for population-specific diagnostic strategies. We propose that systematic investigation of early pregnancy miRNA signatures in diverse populations could enable the development of accessible, accurate, and clinically relevant diagnostic tools for PE.