Objective <p>The aim of this study was to conduct a systematic review of the potential role of placental and plasma micro ribonucleic acids (microRNAs) as early biomarkers for preeclampsia.</p> Materials and Methods <p>The systematic review included nine observational studies with a total sample of 539 women. Of this sample, 252 participants were diagnosed with preeclampsia, while the remaining 287 women formed a control group without the diagnosis. Molecular methods such as reverse transcription polymerase chain reaction (RT-PCR) and next-generation sequencing (NGS) were used to analyse samples. These methods allowed for a detailed evaluation of the expression levels of various microRNAs in placental cells and plasma of the participants.</p> Results <p>The main results demonstrated a significant increase in miR-210 levels in the plasma and placenta of women with preeclampsia: a 2.5-3-fold increase in plasma (p&lt;0.05), and up to 3.5-fold in the placenta (p&lt;0.001). A decrease in the expression of placental-specific microRNAs, such as miR-134 and miR-31-5p, was also observed, with a 3.5-fold reduction (p&lt;0.001).</p> Conclusion <p>These findings provide deeper insight into the molecular mechanisms underlying preeclampsia and open up prospects for the use of microRNAs as early biomarkers for diagnosing preeclampsia and developing new therapeutic approaches.</p>