Objective      To analyze high risk-cesarean scar pregnancy (HR-CSP) related factors which have effect on clinical outcome.       Methods      With a case-control study

30 hospitalized patients for high risk group undergoing the treatment of local excision by laparoscopy and 75 patients for low risk group undergoing the treatment of dilation curettage conducted by laparoscopy were selected from our department of obstetrics and gynecology

during March 2008 and December 2014. The data were extracted from the hospital medical records

and related factors of HR-CSP were identified by univariate analysis and logistic regression analysis with software SPSS17.0.       Results      Student’s t test analysis of continuous variables showed that gestational age at diagnosis  (t=-4.485

P0.01)

maximum diameter of lesion by ultrasonic measurement (t=-5.096

P0.01)

operation time (t=-11.888

P0.01)

intraoperative bleeding amount (t=-5.110

P0.01) and hospitalization days (t=-3.290

P=0.01

P0.05) were HR-CSP related factors. The Chi-squared test  of binary variables showed that ultrasonograghic pattern: mass-type/gestational sac-type (Chi square=35.188

P0.01)

and cardiac activity in gestational sac: yes/no (Chi square=5.392

P=0.020

P0.05) also were the related factors. Logistic regression analysis showed that the maximum diameter of lesion by ultrasonic measurement (OR=0.983

95%CI: 0.970-0.997) and ultrasonograghic pattern: mass-type/gestational sac-type (OR=35.937

95%CI: 15.264-84.611) were independent risk factors of HR-CSP.       Conclusions      The maximum diameter of lesion by ultrasonic measurement and ultrasonograghic pattern are two independent risk factors of HR-CSP.