PURPOSE: The aim of the study is to review the clinical characteristics and risk factors that influence the timing of diagnosis and rupture of interstitial pregnancy, and to evaluate the outcomes of interstitial heterotopic pregnancies after ipsilateral tubal surgery. METHODS: A retrospective statistical analysis was performed on the case data of patients with interstitial pregnancy who met the inclusion criteria and were treated in a single institution. RESULTS: A total of 885 patients with interstitial pregnancy were included in the study, including 55 patients with heterotopic interstitial pregnancies. The gestational age of patients with interstitial rupture was less than those that were diagnosed prior to rupture (P <
0.01). The risk of interstitial pregnancy rupture was higher in women with a history of ipsilateral fallopian tube surgery P <
0.01). In the >
42-day rupture group, the gestation age was less in those with a history of ipsilateral surgery than those without, and the difference was statistically significant (P = 0.005). The shorter the interval, the higher the risk of interstitial pregnancy rupture (P = 0.001). CONCLUSION: Patients with a history of ipsilateral tubal surgery have a higher risk of interstitial pregnancy rupture. The shorter the interval between ipsilateral tubal surgery and interstitial pregnancy, the higher the risk of rupture. For patients with a combined intrauterine and interstitial pregnancy, timely treatment may improve the chances of achieving term live birth.