Predictive Value Of Serum β-hCG Ratio (48h/0h) Combined With Endometrial Thickness In Early Pregnancy Of Unkown Location

Objective To investigate the diagnostic value of human chorionic gonadotropin(β-hCG)ratio(48 h/0 h)and endometrial thickness in predicting the pregnancy outcome of PUL,so as to provide a reference for clinical decision-making in the next step.Methods In prospective observational study,all women classifified with PUL had endometfial thickness measured by transvaginal ultrasonography and serum hCG levels measured at 0 and 48 h to calculate p-hCG ratio(β-hCG 48/β-hCG 0 h).All women were followed up until final diagnosis:spontaneous abortion(SAB),intrauterine pregnancy(IUP),ectopic pregnancy(EP).β-hCG ratio and endometfial thickness of three groups were compared.The best predictor and threshold of EP were determined with receiver operating characteristic curve(ROC),and the evaluation of each index value and its combination were conducted to the diagnosis of EP.Results:(1)A total of 241 PUL were enrolled in this study,of which 89(36.9%)cases were IUP,86(35.7%)SAB,and 66(27.4%)EP.(2)In EP group,serum β-hCG(48h/Oh)ratio were significantly(P<0.001)lower than in IUP group and higher than in SAB group.(3)The endometrial thickness of spontaneous abortion group and ectopic pregnancy group was not statistically significant(P=0.854,AUC was 0.50,95%CI=0.41-0.59).Endometrial thickness were higher in IUP group than those in EP group(P<0.001,AUC was 0.86,95%CI=0.81-0.92).(4)Compared with SAB,the cutoff values of β-HCG ratio and intimal thickness for EP were 0.95 and 5.5,respectively.According to the serum β-hCG ratio,endometrial thickness and the combination of the two,the area under the ROC curves(AUCs)for predicting EP were 0.833,0.501,0.839,respectively,the sensitivitys were 90.9%,100.0%,and 89.4%,respectively,and the specificitys were 80.2%,16.3%,and 82.6%,respectively.Compared with IUP,the cut-off values of β-hCG ratio and endometrial thickness were 1.4 and 15.5,respectively.According to the serum β-hCG ratio,endometrial thickness and the combination of the two,the AUCs for predicting EP were 0.873,0.863,and 0.935,respectively,the sensitivitys were 88.8%,57.3%and 86.5%,respectively and the specificitys were 78.8%,100%and 90.9%,respectively.The diagnosis accordance rate of serum β-hCG ratio combined with endometrial thickness for EP was higher than that of single serum β-hCG ratio(78.8%VS 95.5%),with statistically significant difference(P=0.001).Conclusion:Serum β-hCG ratio has certain value for predicting of PUL.Combined with endometrial thickness can improve the accuracy of prediction,which help to diagnose and treat ectopic pregnancy early.