Objective To investigate the early diagnosis of ectopic pregnancy by transvaginal three-dimensional ultrasound combined with serum carbohydrate antigen 125(CA125),vascular endothelial growth factor(VEGF)and anti-Müllerian hormone(AMH).Methods Totally 96 patients with ectopic pregnancy and 48 pregnant women with normal intrauterine pregnancy diagnosed and treated from May 2019 to June 2022 were selected as study objects.Ultrasonographic parameters(vascularization index[VI],flow index[FI],vascularization flow index[VFI]),and serum CA125,VEGF and AMH were compared between ectopic pregnancy group and intrauterine pregnancy group.Logistic regression model was used to construct diagnostic models by ultrasonic parameters,serum CA125,VEGF and AMH ultrasonic parameters,serum CA125,VEGF and AMH,and six combined parameters.Receiver operating characteristic(ROC)curve was used to evaluate the area under the curve(AUC)values,sensitivities and specificities of ultrasonic parameters(VI,FI,VFI),CA125,VEGF,AMH,and six combined parameters for the diagnosis of ectopic pregnancy.Results The ectopic pregnancy group had lower VI,FI,VFI and AMH and higher CA125 and VEGF than the intrauterine pregnancy group(all P<0.05).ROC curve analysis showed that the AUC of VI,FI,VFI,CA125,VEGF,AMH and combined parameters for the diagnosis of ectopic pregnancy were 0.753,0.644,0.765,0.763,0.768,0.739 and 0.995,respectively.The AUC of the combined parameters was larger than those of VI,FI,VFI,CA125,VEGF and AMH(P<0.05).Conclusion Transvaginal three-dimensional ultrasound combined with serum CA125,VEGF and AMH has high diagnostic value for early ectopic pregnancy and is worthy of clinical application.