Abstract: Objective To explore the predictive value of microRNA-18a (miR-18a) combined with uterine artery blood flow parameters [resistance index (RI), pulse index (PI) and systolic phase velocity/diastolic phase velocity (S/D)] for the early-onset preeclampsia (E-PE). Methods A total of 628 pregnant women undergoing pregnancy checkups were selected in this study and divided into the E-PE group (n=34) and the control group (n=594) according to whether they developed E-PE. The relative expression of mir-18a was detected by real-time quantitative PCR, and RI, PI and S/D parameters were detected by color Doppler ultrasound diagnostic instrument. The predictive value of serum mir-18a, RI, PI and S/D to E-PE were analyzed by subject operating characteristic curve (ROC). Results The relative expression of miR- 18a in serum was lower in the E-PE group than that of the control group, and RI, PI, S/D were higher than those of the control group (P＜0.05). The relative expression of serum miR-18a was negatively correlated with RI, PI, and S/D in E-PE patients (P＜0.05). ROC analysis showed that serum miR-18a, RI and PI can be used to predict the risk of E-PE, and areas under the curve were 0.780 (95%CI: 0.727-0.832), 0.729 (95%CI: 0.644-0.814) and 0.782 (95%CI: 0.695-0.870), respectively. However, S/D had lower predictive value for E-PE, and the product under the curve was 0.602 (95%CI: 0.496- 0.708). miR-18a combined with PI showed a higher predictive value for E-PE, with a sensitivity of 82.35%, a specificity of 83.84%, and a Youden index of 0.662. Conclusion The serum expression of in miR-18a is abnormally low in E-PE patients, and its expression level is negatively correlated with uterine artery blood flow parameters such as RI, PI, and S/D. miR-18a combined with PI has a high predictive value for E-PE.

Key words: pre-eclampsia, diagnosis, microRNAs, ultrasonography, doppler, color, uterine artery, hemodynamics, early-onset preeclampsia, microRNA-18a