Objective To explore the predictive value of serum proprotein convertase subtilisin/kexin type 9(PCSK9)and proprotein convertase subtilisin/kexin type 9(CTRP6)in pregnant women undergoing threatened abortion and fetal protection treatment for pregnancy outcomes.Methods Eighty pregnant women with threatened abortion who were treated in the Second Affiliated Hospital of Shaanxi University of Chinese Medicine from August 2021 to May 2022 were selected as the study subjects.According to the pregnancy outcome,they were grouped into the good pregnancy outcome group(n=62)and the bad pregnancy outcome group(n=18),while another 60 pregnant women with normal pregnancy tests in the hospital were selected as the control group.The serum levels of PCSK9,CTRP6,progesterone and β-human chorionic gonadotropin(β-HCG)were measured by enzyme-linked immunosorbent assay(ELISA).Pearson method was applied to analyze the correlation between serum PCSK9,CTRP6 levels and progesterone and β-HCG levels.Multivariate Logistic regression analysis was applied to analyze the factors affecting the pregnancy outcomes of pregnant women with threatened abortion.The predictive value of serum PCSK9 and CTRP6 on pregnancy outcome of pregnant women with threatened abortion and pregnancy protection treatment was analyzed by the receiver operating characteristic(ROC)curve.Results The level of progesterone(45.65±3.48,38.29±3.54 and 31.56±4.11 nmol/L),β-HCG(32 056.56±4 244.54,23 642.32±3 897.67 and 11 375.56±3 454.35 mIU/L)and CTRP6(436.53±36.23,328.44±31.06 and 277.86±25.56 ng/ml)in control group,good pregnancy outcome group and bad pregnancy outcome group decreased gradually,while the level of PCSK9(64.22±10.35,82.24±13.33 and 114.56±17.67 ng/ml)in the control group,the good pregnancy outcome group and the bad pregnancy outcome group increased gradually,with statistically significant differences(F=129.231,199.334,244.007,111.297,all P＜0.05).Pearson method showed that serum PCSK9 was negatively correlated with progesterone and β-HCG levels(r=-0.545,-0.514,all P＜0.05),and serum CTRP6 was positively correlated with progesterone and β-HCG levels(r=0.567,0.496,all P＜0.05).Multivariate Logistic regression analysis showed that the high level of PCSK9 was an independent risk factor for pregnancy outcome of threatened abortion and fetal protection treatment,and the high level of CTRP6,progesterone and β-HCG were independent protective factors for pregnancy outcome of threatened abortion and fetal protection treatment(P＜0.05).ROC results showed that the area under the curve(AUC)of serum PCSK9 and CTRP6 levels for patients with adverse pregnancy outcomes in the prediction of threatened abortion and fetal protection treatment was 0.843 and 0.849,respectively.The AUC predicted by the combination of the two was 0.941,which was better than that predicted by each individual(Z=1.725,1.882,P＜0.05),with a specificity and a sensitivity of 85.48%,94.44%,respectively.Conclusion The serum PCSK9 level of pregnant women undergoing threatened abortion and fetal protection treatment was obviously increased,and the level of CTRP6 was obviously reduced.This study indicated both have important value in predicting the pregnancy outcomes of pregnant women undergoing threatened abortion and fetal protection treatment.