BackgroundFor patients with recurrent serous borderline ovarian tumors (BOT) who have undergone unilateral salpingo-oophorectomy, there is a risk of reduced or even lost ovarian reserve after the second surgery; therefore, fertility preservation (FP) prior to re-operation in patients of childbearing age is challenging, and has attracted increasing attention. Here, we discuss the multidisciplinary whole-process management of a patient with recurrent serous BOT, from embryo cryopreservation (EC) before re-fertility-sparing surgery (re-FSS) to successful delivery.Case presentationWe describe the treatment of a 28-year-old married, nulliparous female with recurrent serous BOT who requested FP. The patient underwent right salpingo-oophorectomy in July 2020 for serous BOT. In March 2023, B-ultrasound indicated BOT recurrence, and she underwent a second operation. After a multidisciplinary discussion and information on the risks, the patient strongly requested EC. We used letrozole (LE) combined with an antagonist for ovarian stimulation; 16 eggs were obtained, 15 eggs were MII, four embryos on the 3rd day and one blastocyst was formed and cryopreserved. One month later, laparoscopic cystectomy was performed, and pathological examination revealed serous BOT. Three months after the operation, resuscitation and transplantation of one blastocyst did not result in pregnancy through the natural cycle (NC), followed by resuscitation and transfer of two embryos on day 3 through hormone replacement therapy (HRT), which resulted in a successful pregnancy and live healthy male birth. No recurrence was reported at 19 months after re-FSS.ConclusionsThis case highlights the key points of comprehensive multidisciplinary management from the discovery of BOT recurrence, multidisciplinary team (MDT) consultation, ovarian stimulation (OS), egg retrieval, EC, re-FSS, frozen embryo transfer (FET), to delivery. Re-FSS is safe and effective for patients with recurrent serous BOT and strong fertility requirements, and EC before re-FSS is feasible.