MicroRNA-873 is a Potential Serum Biomarker for the Detection of Ectopic Pregnancy.

BACKGROUND Ectopic pregnancy (EP) refers to the implantation of the zygote outside the uterine cavity. In clinical practice, the diagnosis of EP relies on a combination of ultrasound findings and serum human chorionic gonadotrophin (hCG) measurements. However, the need for serial hCG measurements increases the risk of tubal rupture and death, underscoring the need to identify biomarkers for the early detection of EP. METHODS The serum concentrations of 21 microRNAs (miRNAs) associated with pregnancy or with known placental expression, as well as serum hCG and progesterone levels were analyzed 36 patients with viable intrauterine pregnancy (VIP), 30 patients with spontaneous abortion (SA), and 34 patients with EP using specific assay kits and reverse transcription PCR. The diagnostic performance of the different serum markers for detecting EP was analyzed by ROC curve analysis. RESULTS Five miRNAs were differentially expressed between the three groups, of which miR-873 and miR-223 were significantly lower in EP than in VIP and SA patients and did not change significantly according to gestational age, and miR-323 was significantly higher in EP than in VIP and SA. As a single marker, miR-873 had the highest sensitivity for detecting EP at 61.76% (at a fixed specificity of 90%). In comparison, the combination of hCG, progesterone and miR-873 had the highest sensitivity for detecting EP at 79.41% (at a fixed specificity of 90%). CONCLUSION Although further validation in large-scale prospective studies is necessary, our results suggest that miR-873 could be a valuable noninvasive and stable biomarker for the early detection of EP.