Objective:To explore the clinical characteristics,treatments,and pregnancy outcomes of pregnant women with malignant ovari-an tumors.Methods:We retrospectively analyzed the clinical data of 11 patients with pregnancies complicated by malignant ovarian tu-mors,including the pathological types,clinical staging,surgical methods,pregnancy outcomes,and follow-up results from January 2012 to December 2022.Results:Among the eleven patients followed up until October 2023,six had primary ovarian tumors and five had metastat-ic ovarian tumors.Among the six primary ovarian tumors,five were epithelial tumors(one in stage ⅠA,two in stage ⅠC,one in stage ⅢA,one in stage ⅡB)and one was a malignant germ cell tumor(stage ⅠA).Four patients were diagnosed at stage Ⅰ:one in early pregnancy who continued the pregnancy and underwent tumor surgery post-delivery,and three in late pregnancy who under went tumor surgery dur-ing cesarean section or postpartum.Two patients were diagnosed at stage Ⅲ:one in early pregnancy with surgery after the termination of pregnancy,and one in late pregnancy with surgery during a cesarean section.Five patients had successful births,including two premature and three full-term births,all alive and healthy.The six patients with primary ovarian tumors were followed up for 18-133 months,and all survived.Five patients had ovarian metastatic tumors,including four cases of Krukenberg tumors and one of a cervical tumor.Two patients were diagnosed in the first trimester and underwent tumor reduction post-abortion.One patient was diagnosed in the second trimester,had to continue the pregnancy,and underwent tumor reduction post-delivery.Two patients were diagnosed in the third trimester:one under-went cesarean section and ovarian tumor resection simultaneously,and the other underwent tumor resection post-delivery.Three patients had successful births,all premature but alive.One of the five patients with ovarian metastatic tumors was lost to follow-up;the remaining four were followed up for 3-22 months,and all deceased.Conclusions:The prognosis for patients with pregnancies complicated by ovarian primary tumors is favorable,whereas the prognosis for patients with pregnancies complicated by ovarian metastatic tumors is poor,neces-sitating greater clinical attention.