Abstract: Objective To explore the expression significance of carcinoembryonic antigen 125 (CA125), microRNA-145 (miR-145), microRNA-141-3p (miR-141-3p), and monocyte chemoattractant protein-1 (MCP-1) in patients with endometriosis (EM) and their relationship with pregnancy outcomes. 
Methods A total of 117 EM patients were selected as the EM group, and 80 healthy women who underwent physical examinations during the same period were selected as the control group. The serum levels of CA125, miR-145, miR-141-3p, and MCP-1 were compared between the two groups. The serum levels of CA125, miR-145, miR-141-3p, and MCP-1 in EM patients with different r-AFS stages were compared. Spearman′s test was used to analyze the correlation between serum CA125, miR-145, miR-141-3p, MCP-1, and r-AFS stages in EM patients. EM patients were followed up for 2 years after laparoscopic surgery to analyze pregnancy outcomes. Clinical data were compared between the good pregnancy outcome group and the poor pregnancy outcome group. Logistic regression models were used to analyze the risk factors and protective factors for poor pregnancy outcomes in EM. Receiver operating characteristic (ROC) curves were used to analyze the predictive value of serum CA125, miR-145, miR-141-3p, and MCP-1 for poor pregnancy outcomes in EM. 
Results Compared with the control group, the serum levels of CA125, MCP-1, and miR-145 in the EM group were significantly increased (P＜0.05), while the serum levels of miR-141-3p were significantly decreased (P＜0.05). Compared with those before surgery, the serum levels of CA125, MCP-1, and miR-145 in EM patients were significantly reduced at 48 h after surgery (P＜0.05), while the serum levels of miR-141-3p were significantly increased (P＜0.05). Compared with stages Ⅰ-Ⅱ, preoperative serum levels of CA125, MCP-1, and miR-145 were significantly increased (P＜0.05) in stage Ⅲ-Ⅳ patients, while miR-141-3p levels were significantly decreased (P＜0.05). Spearman′s test showed that preoperative serum CA125, MCP-1 and miR-145 were positively correlated with r-AFS staging (r=0.640, 0.581, 0.637, P＜0.001), while serum miR-141-3p was negatively correlated with r-AFS staging (r=-0.605, P＜0.001). All 117 EM patients were followed up for 2 years after surgery. During the follow-up period, 5 patients were to fllow-up and 112 patients were followed up. Fifty-four patients had poor pregnancy outcomes, with an incidence rate of 48.21%. Compared with the good pregnancy outcome group, the proportion of r-AFS staging in stages Ⅲ-Ⅳ, preoperative CA125, preoperative MCP-1, and preoperative miR-145 in the poor pregnancy outcome group was significantly increased (P＜0.05), while the proportion of preoperative anti Mullerian hormone, miR-141-3p, and simple ovarian type was significantly decreased (P＜0.05). The results of the logistic regression model showed that high r-AFS stage, preoperative CA125, preoperative MCP-1, and preoperative miR-145 were risk factors for poor pregnancy outcomes in EM patients (OR=1.746, 2.367, 2.760, 1.997, P＜0.05), while preoperative anti Mullerian hormone and miR-141-3p were protective factors for poor pregnancy outcomes in EM patients (OR=0.802, 0.640, P＜0.05). ROC curve was drawn, and it was found that the area under the ROC curve (AUC), sensitivity, and specificity of serum CA125, miR-145, miR-141-3p, and MCP-1 in combination for the prediction of adverse pregnancy outcomes in EM were 0.883, 83.32%, and 84.52%, respectively, which were significantly better than single detection (P＜0.05). 
Conclusion Serum CA125, MCP-1, and miR-145 are highly expressed in EM patients, while miR-141-3p is lowly expressed. This expression level is closely related to the staging of EM and pregnancy outcome. Combined detection of these four indicators can help predict adverse pregnancy outcomes in EM. 

Key words: endometriosis, carcinoembryonic antigen, microRNA