Both borderline ovarian tumors (BOTs) and complex atypical hyperplasia (CAH) are low malignant disease of the female reproductive system, which can be treated with fertility-preserving treatments for women of reproductive age. Assisted reproductive technology (ART) is used to achieve pregnancy in infertile women. Although treatments for the isolated disease have some guidelines, protocol making is not that simple when abnormalities coexist. Here, a case of patient with BOT, a history of CAH, and infertility is presented. After fertility-preserving surgery and in-vitro fertilization and embryo transfer (IVF-ET), the patient successfully achieved a twin pregnancy leading to term live birth. The treatment process towards the complex situation is available for future reference. Consent: We present the first case with abnormalities co-existence and the process of combined treatment is effective and available for future reference.