Abstract: This study was to investigate the diagnostic value of transvaginal Doppler color ultrasound combined with serum human chorionic gonadotropin (β-HCG) in cesarean scar pregnancy. From April 2018 to April 2019, 56 patients with suspected cesarean scar pregnancy in our hospital were selected as subjects. All of them were examined by transvaginal Doppler color ultrasound and serum β-HCG levels, and confirmed by surgery and/or histopathological examination. The results showed that the characteristics of transvaginal Doppler color ultrasound in patients with CSP included:the gestational sac was visible in the myometrium of lower front wall, thinning of the myometrium between the gestational sac and the bladder, high speed and low resistance signal around the gestational sac. The increase of serum β-HCG in 48 h in CSP patients was lower than that in non-CSP patients (t=7.425, P=0.000). The area under the ROC curve of the increase of serum β-HCG in 48 h was 0.919, and the optimal cut-off value was 64.22%. At this time, the sensitivity of diagnosis was 80.00%, and the specificity was 88.90%. Compared with surgery and/or pathological examination, the consistency of single diagnosis and combined diagnosis was good, and there was no difference in the sensitivity, specificity, positive predictive value, negative predictive value and accuracy of CSP diagnosis,P>0.05. The two methods can be used as a reference to reduce the misdiagnosis rate and missed diagnosis rate.

Key words: Doppler color ultrasound, serum human chorionic gonadotropin, cesarean scar pregnancy, diagnosis