With the increasing popularity of assisted reproductive technology, the incidence of ectopic pregnancy has increased significantly. According to the literature, the incidence of EP after IVF-ET ranges from 4% to 11%. The overall incidence of ectopic pregnancy in our center was 7.5%, which was in accordance with the literature. The incidence of ectopic pregnancy in tubal infertility was 10.3%, hydrocele was 15% and history of tubal reconstruction surgery was 22.2%. The incidence of simultaneous intrauterine and extrauterine pregnancies was 3.7%, much higher than the 0.6% in spontaneous pregnancies. In the West, the incidence of ectopic pregnancy in the general population is about 2% in natural pregnancies, but it can be as high as 20% in those who have undergone tubal surgery. The risk factors for ectopic pregnancy (EP) in spontaneous pregnancies are: Mycoplasma urealyticum (UU) infection in the reproductive tract is an important cause of EP, and UU may increase the incidence of EP by causing tubal and pelvic lesions. Strandell et al. compared 725 pregnancies in 3019 ETs, including 29 ectopic pregnancies, and used logistic regression analysis to conclude that tubal infertility was the most important risk factor for EP after IVF-ET. Zouves et al. analyzed 17 cases of ectopic pregnancy after IVF-ET and found that 14 cases (82.4%) occurred in patients with tubal lesions, with significant differences, and inferred that pathological changes in the fallopian tubes were important factors in the development of ectopic pregnancy after IVF-ET. The most important risk factor for the development of EP after IVF-ET was tubal reconstruction surgery. In our study, we analyzed 144 cycles of tubal factor infertility and 51 cycles of non-tubal factor infertility and found that 6 ectopic pregnancies occurred in patients with tubal factor infertility, with a significant difference of P < 0.0 5, thus indicating that tubal infertility is a risk factor for the development of ectopic pregnancy after IVF-ET. Among the 17 cycles analyzed in patients with a history of tubal reconstruction surgery and 99 cycles in other patients with tubal infertility, the incidence of ectopic pregnancy was 22.2% and 9.7%, respectively, with a trend toward higher incidence of EP, but without statistical significance, which may require a larger sample size for study. We hypothesize that the mechanism of ectopic pregnancy after IVF-ET for tubal infertility is that most or some of the embryos may enter the fallopian tube during ET, and under the action of the corpus luteum, most of the embryos automatically move back to the uterine cavity, while the lesions of the fallopian tube prevent them from returning to the uterine cavity, thus leading to the formation of EP. This can be illustrated by the finding of Knutzen et al. in a simulated ET that the ET fluid injected into the uterine cavity with 40 μl of rays could not penetrate, and in 38.2% of patients the ET fluid partially or completely entered the fallopian tube. Blazar et al. analyzed 63 patients with tubal effusion and 183 patients with tubal infertility without tubal effusion and concluded that the incidence of EP was similar, while Ng et al. concluded that the incidence of EP was significantly higher in patients with tubal effusion. However, in our analysis, the incidence of EP in patients with tubal effusion was 15%, which was higher than that in the non-tubal effusion group (7.9%), and there was a tendency to increase, but it was not statistically significant. Ian et al. reported that an increase in the number of embryos transferred may lead to an increased incidence of simultaneous intrauterine and extrauterine pregnancies; Yovich et al. reported that placement of the transfer tube in the lower and middle uterine cavity may decrease the incidence of EP; Marcus et al. reported that an increase in the volume of transfer fluid at the time of transfer may increase the incidence of EP; JobSpira et al. reported that chromosomal abnormalities in eggs may lead to EP. Early diagnosis of ectopic pregnancy after IVF-ET is important and relies on blood hCG testing and vaginal ultrasound. A significant decrease in blood hCG 14 d after ET in patients is an important predictor of EP, and vaginal ultrasound is the most effective method. Patients with high-risk factors should be monitored more closely and the pelvis should be carefully scanned even if intrauterine pregnancy is confirmed to improve early diagnosis of EP to prevent serious complications. The prognosis of intrauterine fetuses, especially in patients with HEP, is generally good if they are detected early and operated early. In this study, a total of 3 patients with HEP were found to have intrauterine gestational sacs combined with adnexal gestational sacs or mixed extra-ovarian masses on ultrasound 14 d after positive urinary hCG, and early caesarean section revealed thickening of one fallopian tube and resection of the affected fallopian tube, which was pathologically confirmed as tubal pregnancy, and one of them delivered a full-term normal fetus. Conclusion: Tubal factor infertility is a risk factor for ectopic pregnancy after IVF-ET, and monitoring should be enhanced in high-risk patients.